diff --git a/projects/SelfTest/Baselines/console.std.approved.txt b/projects/SelfTest/Baselines/console.std.approved.txt
index 49f184e9..4a061ae7 100644
--- a/projects/SelfTest/Baselines/console.std.approved.txt
+++ b/projects/SelfTest/Baselines/console.std.approved.txt
@@ -1002,6 +1002,6 @@ with expansion:
   "first" == "second"
 
 ===============================================================================
-test cases: 171 | 121 passed | 46 failed |  4 failed as expected
-assertions: 844 | 729 passed | 94 failed | 21 failed as expected
+test cases: 174 | 124 passed | 46 failed |  4 failed as expected
+assertions: 908 | 793 passed | 94 failed | 21 failed as expected
 
diff --git a/projects/SelfTest/Baselines/console.sw.approved.txt b/projects/SelfTest/Baselines/console.sw.approved.txt
index e74a3348..c27c1098 100644
--- a/projects/SelfTest/Baselines/console.sw.approved.txt
+++ b/projects/SelfTest/Baselines/console.sw.approved.txt
@@ -5692,6 +5692,50 @@ MatchersTests.cpp:<line number>: FAILED:
 with expansion:
   "this string contains 'abc' as a substring" starts with: "string"
 
+-------------------------------------------------------------------------------
+String
+  empty string
+-------------------------------------------------------------------------------
+String.tests.cpp:<line number>
+...............................................................................
+
+String.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( empty.empty() )
+with expansion:
+  true
+
+String.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( empty.size() == 0 )
+with expansion:
+  0 == 0
+
+String.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( std::strcmp( empty.c_str(), "" ) == 0 )
+with expansion:
+  0 == 0
+
+-------------------------------------------------------------------------------
+String
+  from literal
+-------------------------------------------------------------------------------
+String.tests.cpp:<line number>
+...............................................................................
+
+String.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.empty() == false )
+with expansion:
+  false == false
+
+String.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.size() == 5 )
+with expansion:
+  5 == 5
+
 -------------------------------------------------------------------------------
 String matchers
 -------------------------------------------------------------------------------
@@ -5722,6 +5766,504 @@ PASSED:
 with expansion:
   "this string contains 'abc' as a substring" ends with: "substring"
 
+-------------------------------------------------------------------------------
+StringBuilder
+  basic
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.capacity() == 0 )
+with expansion:
+  0 == 0
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.size() == 0 )
+with expansion:
+  0 == 0
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.capacity() == 32 )
+with expansion:
+  32 == 32
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.size() == 0 )
+with expansion:
+  0 == 0
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.capacity() == 32 )
+with expansion:
+  32 == 32
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb.size() == 5 )
+with expansion:
+  5 == 5
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s == "hello" )
+with expansion:
+  {?} == "hello"
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.size() == 5 )
+with expansion:
+  5 == 5
+
+-------------------------------------------------------------------------------
+StringBuilder
+  concatenation
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s == "hello world" )
+with expansion:
+  {?} == "hello world"
+
+-------------------------------------------------------------------------------
+StringBuilder
+  concat & move
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s == "hello world" )
+with expansion:
+  {?} == "hello world"
+
+-------------------------------------------------------------------------------
+StringBuilder
+  reserved
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb16.capacity() == 16 )
+with expansion:
+  16 == 16
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( sb16.capacity() == 16 )
+with expansion:
+  16 == 16
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s == "hello world" )
+with expansion:
+  {?} == "hello world"
+
+-------------------------------------------------------------------------------
+StringBuilder
+  from String
+  copy
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2 == s )
+with expansion:
+  {?} == {?}
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2.c_str() != s.c_str() )
+with expansion:
+  "hello" != "hello"
+
+-------------------------------------------------------------------------------
+StringBuilder
+  from String
+  move from uniquely owned string
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2 == "hello" )
+with expansion:
+  {?} == "hello"
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2.c_str() == originalPointer )
+with expansion:
+  "hello" == "hello"
+
+-------------------------------------------------------------------------------
+StringBuilder
+  from String
+  move from shared string (copies)
+-------------------------------------------------------------------------------
+StringBuilder.tests.cpp:<line number>
+...............................................................................
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2 == "hello" )
+with expansion:
+  {?} == "hello"
+
+StringBuilder.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s2.c_str() != originalPointer )
+with expansion:
+  "hello" != "hello"
+
+-------------------------------------------------------------------------------
+StringRef
+  Empty string
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( empty.empty() )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( empty.size() == 0 )
+with expansion:
+  0 == 0
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( std::strcmp( empty.c_str(), "" ) == 0 )
+with expansion:
+  0 == 0
+
+-------------------------------------------------------------------------------
+StringRef
+  From string literal
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.empty() == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.size() == 5 )
+with expansion:
+  5 == 5
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isSubstring( s ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( std::strcmp( rawChars, "hello" ) == 0 )
+with expansion:
+  0 == 0
+
+-------------------------------------------------------------------------------
+StringRef
+  From string literal
+  c_str() does not cause copy
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( s ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.c_str() == rawChars )
+with expansion:
+  "hello" == "hello"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( s ) == false )
+with expansion:
+  false == false
+
+-------------------------------------------------------------------------------
+StringRef
+  From sub-string
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( original == "original" )
+with expansion:
+  {?} == "original"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isSubstring( original ) )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( original ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isSubstring( original ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( original ) )
+with expansion:
+  true
+
+-------------------------------------------------------------------------------
+StringRef
+  Substrings
+  zero-based substring
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( ss.empty() == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( ss.size() == 5 )
+with expansion:
+  5 == 5
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( std::strcmp( ss.c_str(), "hello" ) == 0 )
+with expansion:
+  0 == 0
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( ss == "hello" )
+with expansion:
+  {?} == "hello"
+
+-------------------------------------------------------------------------------
+StringRef
+  Substrings
+  c_str() causes copy
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isSubstring( ss ) )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( ss ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( rawChars == data( s ) )
+with expansion:
+  "hello world!" == "hello world!"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( ss.c_str() != rawChars )
+with expansion:
+  "hello" != "hello world!"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isSubstring( ss ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( ss ) )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( data( ss ) != data( s ) )
+with expansion:
+  "hello" != "hello world!"
+
+-------------------------------------------------------------------------------
+StringRef
+  Substrings
+  non-zero-based substring
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( ss.size() == 6 )
+with expansion:
+  6 == 6
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( std::strcmp( ss.c_str(), "world!" ) == 0 )
+with expansion:
+  0 == 0
+
+-------------------------------------------------------------------------------
+StringRef
+  Substrings
+  Pointer values of full refs should match
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.c_str() == s2.c_str() )
+with expansion:
+  "hello world!" == "hello world!"
+
+-------------------------------------------------------------------------------
+StringRef
+  Substrings
+  Pointer values of substring refs should not match
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( s.c_str() != ss.c_str() )
+with expansion:
+  "hello world!" != "hello"
+
+-------------------------------------------------------------------------------
+StringRef
+  Comparisons
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( StringRef("hello") == StringRef("hello") )
+with expansion:
+  {?} == {?}
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( StringRef("hello") != StringRef("cello") )
+with expansion:
+  {?} != {?}
+
+-------------------------------------------------------------------------------
+StringRef
+  From string
+  Copied
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( copied == "hot potato" )
+with expansion:
+  {?} == "hot potato"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( str == "hot potato" )
+with expansion:
+  {?} == "hot potato"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( copied ) == false )
+with expansion:
+  false == false
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( data( copied ) == originalPointer )
+with expansion:
+  "hot potato" == "hot potato"
+
+-------------------------------------------------------------------------------
+StringRef
+  From string
+  Moved
+-------------------------------------------------------------------------------
+StringRef.tests.cpp:<line number>
+...............................................................................
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( copied == "hot potato" )
+with expansion:
+  {?} == "hot potato"
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( isOwned( copied ) )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( str.empty() )
+with expansion:
+  true
+
+StringRef.tests.cpp:<line number>:
+PASSED:
+  REQUIRE( data( copied ) == originalPointer )
+with expansion:
+  "hot potato" == "hot potato"
+
 hello
 hello
 -------------------------------------------------------------------------------
@@ -8352,6 +8894,6 @@ MiscTests.cpp:<line number>:
 PASSED:
 
 ===============================================================================
-test cases: 171 | 120 passed | 47 failed |  4 failed as expected
-assertions: 846 | 729 passed | 96 failed | 21 failed as expected
+test cases: 174 | 123 passed | 47 failed |  4 failed as expected
+assertions: 910 | 793 passed | 96 failed | 21 failed as expected
 
diff --git a/projects/SelfTest/Baselines/junit.sw.approved.txt b/projects/SelfTest/Baselines/junit.sw.approved.txt
index cae1e4bf..91e2307a 100644
--- a/projects/SelfTest/Baselines/junit.sw.approved.txt
+++ b/projects/SelfTest/Baselines/junit.sw.approved.txt
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <testsuitesspanner>
-  <testsuite name="<exe-name>" errors="15" failures="82" tests="847" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
+  <testsuite name="<exe-name>" errors="15" failures="82" tests="911" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
     <testcase classname="<exe-name>.global" name="# A test name that starts with a #" time="{duration}"/>
     <testcase classname="<exe-name>.global" name="#748 - captures with unexpected exceptions/outside assertions" time="{duration}">
       <error type="TEST_CASE">
@@ -512,7 +512,28 @@ Message from section two
 MatchersTests.cpp:<line number>
       </failure>
     </testcase>
+    <testcase classname="<exe-name>.global" name="String/empty string" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="String/from literal" time="{duration}"/>
     <testcase classname="<exe-name>.global" name="String matchers" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/basic" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/concatenation" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/concat &amp; move" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/reserved" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/from String/copy" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/from String/move from uniquely owned string" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringBuilder/from String/move from shared string (copies)" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Empty string" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/From string literal" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/From string literal/c_str() does not cause copy" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/From sub-string" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Substrings/zero-based substring" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Substrings/c_str() causes copy" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Substrings/non-zero-based substring" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Substrings/Pointer values of full refs should match" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Substrings/Pointer values of substring refs should not match" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/Comparisons" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/From string/Copied" time="{duration}"/>
+    <testcase classname="<exe-name>.global" name="StringRef/From string/Moved" time="{duration}"/>
     <testcase classname="<exe-name>.global" name="Strings can be rendered with colour" time="{duration}">
       <system-out>
 hello
diff --git a/projects/SelfTest/Baselines/xml.sw.approved.txt b/projects/SelfTest/Baselines/xml.sw.approved.txt
index 948cff19..4e65d8ce 100644
--- a/projects/SelfTest/Baselines/xml.sw.approved.txt
+++ b/projects/SelfTest/Baselines/xml.sw.approved.txt
@@ -6358,6 +6358,55 @@ Message from section two
       </Expression>
       <OverallResult success="false"/>
     </TestCase>
+    <TestCase name="String" tags="[Strings]" filename="projects/<exe-name>/String.tests.cpp" >
+      <Section name="empty string" filename="projects/<exe-name>/String.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/String.tests.cpp" >
+          <Original>
+            empty.empty()
+          </Original>
+          <Expanded>
+            true
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/String.tests.cpp" >
+          <Original>
+            empty.size() == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/String.tests.cpp" >
+          <Original>
+            std::strcmp( empty.c_str(), "" ) == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <OverallResults successes="3" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="from literal" filename="projects/<exe-name>/String.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/String.tests.cpp" >
+          <Original>
+            s.empty() == false
+          </Original>
+          <Expanded>
+            false == false
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/String.tests.cpp" >
+          <Original>
+            s.size() == 5
+          </Original>
+          <Expanded>
+            5 == 5
+          </Expanded>
+        </Expression>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <OverallResult success="true"/>
+    </TestCase>
     <TestCase name="String matchers" tags="[matchers]" filename="projects/<exe-name>/MatchersTests.cpp" >
       <Expression success="true" type="REQUIRE_THAT" filename="projects/<exe-name>/MatchersTests.cpp" >
         <Original>
@@ -6393,6 +6442,571 @@ Message from section two
       </Expression>
       <OverallResult success="true"/>
     </TestCase>
+    <TestCase name="StringBuilder" tags="[Strings]" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+      <Section name="basic" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.capacity() == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.size() == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.capacity() == 32
+          </Original>
+          <Expanded>
+            32 == 32
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.size() == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.capacity() == 32
+          </Original>
+          <Expanded>
+            32 == 32
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb.size() == 5
+          </Original>
+          <Expanded>
+            5 == 5
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            s == "hello"
+          </Original>
+          <Expanded>
+            {?} == "hello"
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            s.size() == 5
+          </Original>
+          <Expanded>
+            5 == 5
+          </Expanded>
+        </Expression>
+        <OverallResults successes="8" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="concatenation" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            s == "hello world"
+          </Original>
+          <Expanded>
+            {?} == "hello world"
+          </Expanded>
+        </Expression>
+        <OverallResults successes="1" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="concat &amp; move" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            s == "hello world"
+          </Original>
+          <Expanded>
+            {?} == "hello world"
+          </Expanded>
+        </Expression>
+        <OverallResults successes="1" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="reserved" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb16.capacity() == 16
+          </Original>
+          <Expanded>
+            16 == 16
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            sb16.capacity() == 16
+          </Original>
+          <Expanded>
+            16 == 16
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Original>
+            s == "hello world"
+          </Original>
+          <Expanded>
+            {?} == "hello world"
+          </Expanded>
+        </Expression>
+        <OverallResults successes="3" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="from String" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Section name="copy" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2 == s
+            </Original>
+            <Expanded>
+              {?} == {?}
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2.c_str() != s.c_str()
+            </Original>
+            <Expanded>
+              "hello" != "hello"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="2" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="from String" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Section name="move from uniquely owned string" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2 == "hello"
+            </Original>
+            <Expanded>
+              {?} == "hello"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2.c_str() == originalPointer
+            </Original>
+            <Expanded>
+              "hello" == "hello"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="2" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="from String" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+        <Section name="move from shared string (copies)" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2 == "hello"
+            </Original>
+            <Expanded>
+              {?} == "hello"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringBuilder.tests.cpp" >
+            <Original>
+              s2.c_str() != originalPointer
+            </Original>
+            <Expanded>
+              "hello" != "hello"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="2" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <OverallResult success="true"/>
+    </TestCase>
+    <TestCase name="StringRef" tags="[Strings]" filename="projects/<exe-name>/StringRef.tests.cpp" >
+      <Section name="Empty string" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            empty.empty()
+          </Original>
+          <Expanded>
+            true
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            empty.size() == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            std::strcmp( empty.c_str(), "" ) == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <OverallResults successes="3" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="From string literal" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            s.empty() == false
+          </Original>
+          <Expanded>
+            false == false
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            s.size() == 5
+          </Original>
+          <Expanded>
+            5 == 5
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            isSubstring( s ) == false
+          </Original>
+          <Expanded>
+            false == false
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            std::strcmp( rawChars, "hello" ) == 0
+          </Original>
+          <Expanded>
+            0 == 0
+          </Expanded>
+        </Expression>
+        <Section name="c_str() does not cause copy" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( s ) == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              s.c_str() == rawChars
+            </Original>
+            <Expanded>
+              "hello" == "hello"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( s ) == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <OverallResults successes="3" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="7" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="From sub-string" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            original == "original"
+          </Original>
+          <Expanded>
+            {?} == "original"
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            isSubstring( original )
+          </Original>
+          <Expanded>
+            true
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            isOwned( original ) == false
+          </Original>
+          <Expanded>
+            false == false
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            isSubstring( original ) == false
+          </Original>
+          <Expanded>
+            false == false
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            isOwned( original )
+          </Original>
+          <Expanded>
+            true
+          </Expanded>
+        </Expression>
+        <OverallResults successes="5" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Substrings" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="zero-based substring" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              ss.empty() == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              ss.size() == 5
+            </Original>
+            <Expanded>
+              5 == 5
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              std::strcmp( ss.c_str(), "hello" ) == 0
+            </Original>
+            <Expanded>
+              0 == 0
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              ss == "hello"
+            </Original>
+            <Expanded>
+              {?} == "hello"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="4" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="4" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Substrings" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="c_str() causes copy" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isSubstring( ss )
+            </Original>
+            <Expanded>
+              true
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( ss ) == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              rawChars == data( s )
+            </Original>
+            <Expanded>
+              "hello world!" == "hello world!"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              ss.c_str() != rawChars
+            </Original>
+            <Expanded>
+              "hello" != "hello world!"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isSubstring( ss ) == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( ss )
+            </Original>
+            <Expanded>
+              true
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              data( ss ) != data( s )
+            </Original>
+            <Expanded>
+              "hello" != "hello world!"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="7" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="7" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Substrings" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="non-zero-based substring" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              ss.size() == 6
+            </Original>
+            <Expanded>
+              6 == 6
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              std::strcmp( ss.c_str(), "world!" ) == 0
+            </Original>
+            <Expanded>
+              0 == 0
+            </Expanded>
+          </Expression>
+          <OverallResults successes="2" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Substrings" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="Pointer values of full refs should match" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              s.c_str() == s2.c_str()
+            </Original>
+            <Expanded>
+              "hello world!" == "hello world!"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="1" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="1" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Substrings" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="Pointer values of substring refs should not match" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              s.c_str() != ss.c_str()
+            </Original>
+            <Expanded>
+              "hello world!" != "hello"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="1" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="1" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="Comparisons" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            StringRef("hello") == StringRef("hello")
+          </Original>
+          <Expanded>
+            {?} == {?}
+          </Expanded>
+        </Expression>
+        <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Original>
+            StringRef("hello") != StringRef("cello")
+          </Original>
+          <Expanded>
+            {?} != {?}
+          </Expanded>
+        </Expression>
+        <OverallResults successes="2" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="From string" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="Copied" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              copied == "hot potato"
+            </Original>
+            <Expanded>
+              {?} == "hot potato"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              str == "hot potato"
+            </Original>
+            <Expanded>
+              {?} == "hot potato"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( copied ) == false
+            </Original>
+            <Expanded>
+              false == false
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              data( copied ) == originalPointer
+            </Original>
+            <Expanded>
+              "hot potato" == "hot potato"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="4" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="4" failures="0" expectedFailures="0"/>
+      </Section>
+      <Section name="From string" filename="projects/<exe-name>/StringRef.tests.cpp" >
+        <Section name="Moved" filename="projects/<exe-name>/StringRef.tests.cpp" >
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              copied == "hot potato"
+            </Original>
+            <Expanded>
+              {?} == "hot potato"
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              isOwned( copied )
+            </Original>
+            <Expanded>
+              true
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              str.empty()
+            </Original>
+            <Expanded>
+              true
+            </Expanded>
+          </Expression>
+          <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/StringRef.tests.cpp" >
+            <Original>
+              data( copied ) == originalPointer
+            </Original>
+            <Expanded>
+              "hot potato" == "hot potato"
+            </Expanded>
+          </Expression>
+          <OverallResults successes="4" failures="0" expectedFailures="0"/>
+        </Section>
+        <OverallResults successes="4" failures="0" expectedFailures="0"/>
+      </Section>
+      <OverallResult success="true"/>
+    </TestCase>
     <TestCase name="Strings can be rendered with colour" tags="[.][.colour][hide]" filename="projects/<exe-name>/TestMain.cpp" >
       <OverallResult success="true">
         <StdOut>
@@ -9166,7 +9780,7 @@ spanner      <OverallResult success="true"/>
       </Section>
       <OverallResult success="true"/>
     </TestCase>
-    <OverallResults successes="729" failures="97" expectedFailures="21"/>
+    <OverallResults successes="793" failures="97" expectedFailures="21"/>
   </Group>
-  <OverallResults successes="729" failures="96" expectedFailures="21"/>
+  <OverallResults successes="793" failures="96" expectedFailures="21"/>
 </Catch>