Performance improvement in AssertionInfo.

By using char const * instead of std::string we avoid significant
copying per assertion.  In a simple loop with 10000000 CHECKS on
my system, this reduces the run time from 9.8s to 5.8s.

This change is at the expense of no longer capturing the second arg,
which no currently existing test notices.

include/internal/catch_assertionresult.h

@@ -40,14 +40,14 @@ namespace Catch {
     struct AssertionInfo
     {
         AssertionInfo() {}
-        AssertionInfo(  std::string const& _macroName,
+        AssertionInfo(  char const * _macroName,
                         SourceLineInfo const& _lineInfo,
-                        std::string const& _capturedExpression,
+                        char const * _capturedExpression,
                         ResultDisposition::Flags _resultDisposition );
 
-        std::string macroName;
+        char const * macroName;
         SourceLineInfo lineInfo;
-        std::string capturedExpression;
+        char const * capturedExpression;
         ResultDisposition::Flags resultDisposition;
     };
 

include/internal/catch_assertionresult.hpp

@@ -13,9 +13,9 @@
 namespace Catch {
 
 
-    AssertionInfo::AssertionInfo(   std::string const& _macroName,
+    AssertionInfo::AssertionInfo(   char const * _macroName,
                                     SourceLineInfo const& _lineInfo,
-                                    std::string const& _capturedExpression,
+                                    char const * _capturedExpression,
                                     ResultDisposition::Flags _resultDisposition )
     :   macroName( _macroName ),
         lineInfo( _lineInfo ),
@@ -47,7 +47,7 @@ namespace Catch {
     }
 
     bool AssertionResult::hasExpression() const {
-        return !m_info.capturedExpression.empty();
+        return m_info.capturedExpression[0] != 0;
     }
 
     bool AssertionResult::hasMessage() const {
@@ -61,10 +61,10 @@ namespace Catch {
             return m_info.capturedExpression;
     }
     std::string AssertionResult::getExpressionInMacro() const {
-        if( m_info.macroName.empty() )
+        if( m_info.macroName[0] == 0 )
             return m_info.capturedExpression;
         else
-            return m_info.macroName + "( " + m_info.capturedExpression + " )";
+            return std::string(m_info.macroName) + "( " + m_info.capturedExpression + " )";
     }
 
     bool AssertionResult::hasExpandedExpression() const {

include/internal/catch_result_builder.hpp

@@ -28,7 +28,7 @@ namespace Catch {
                                     char const* capturedExpression,
                                     ResultDisposition::Flags resultDisposition,
                                     char const* secondArg )
-    :   m_assertionInfo( macroName, lineInfo, capturedExpressionWithSecondArgument( capturedExpression, secondArg ), resultDisposition ),
+    :   m_assertionInfo( macroName, lineInfo, capturedExpression, resultDisposition ),
         m_shouldDebugBreak( false ),
         m_shouldThrow( false ),
         m_guardException( false )

include/internal/catch_run_context.hpp

@@ -150,7 +150,7 @@ namespace Catch {
             static_cast<void>(m_reporter->assertionEnded(AssertionStats(result, m_messages, m_totals)));
 
             // Reset working state
-            m_lastAssertionInfo = AssertionInfo( std::string(), m_lastAssertionInfo.lineInfo, "{Unknown expression after the reported line}" , m_lastAssertionInfo.resultDisposition );
+            m_lastAssertionInfo = AssertionInfo( "", m_lastAssertionInfo.lineInfo, "{Unknown expression after the reported line}" , m_lastAssertionInfo.resultDisposition );
             m_lastResult = result;
         }
 
@@ -280,7 +280,7 @@ namespace Catch {
             double duration = 0;
             m_shouldReportUnexpected = true;
             try {
-                m_lastAssertionInfo = AssertionInfo( "TEST_CASE", testCaseInfo.lineInfo, std::string(), ResultDisposition::Normal );
+                m_lastAssertionInfo = AssertionInfo( "TEST_CASE", testCaseInfo.lineInfo, "", ResultDisposition::Normal );
 
                 seedRng( *m_config );
 
@@ -332,9 +332,9 @@ namespace Catch {
     private:
 
         ResultBuilder makeUnexpectedResultBuilder() const {
-            return ResultBuilder(   m_lastAssertionInfo.macroName.c_str(),
+            return ResultBuilder(   m_lastAssertionInfo.macroName,
                                     m_lastAssertionInfo.lineInfo,
-                                    m_lastAssertionInfo.capturedExpression.c_str(),
+                                    m_lastAssertionInfo.capturedExpression,
                                     m_lastAssertionInfo.resultDisposition );
         }