Add -Wmissing-declarations to the SelfTest project

This required some clean-up in our test files

projects/SelfTest/UsageTests/Decomposition.tests.cpp

@@ -9,6 +9,8 @@
 #include <iostream>
 #include <cstdio>
 
+namespace {
+
 struct truthy {
     truthy(bool b):m_value(b){}
     operator bool() const {
@@ -22,6 +24,8 @@ std::ostream& operator<<(std::ostream& o, truthy) {
     return o;
 }
 
+} // end anonymous namespace
+
 #include "catch.hpp"
 
 TEST_CASE( "Reconstruction should be based on stringification: #914" , "[Decomposition][failing][.]") {

projects/SelfTest/UsageTests/EnumToString.tests.cpp

@@ -1,22 +1,24 @@
 #include "catch.hpp"
 
 
+namespace {
 // Enum without user-provided stream operator
 enum Enum1 { Enum1Value0, Enum1Value1 };
 
-TEST_CASE( "toString(enum)", "[toString][enum]" ) {
-    Enum1 e0 = Enum1Value0;
-    CHECK( ::Catch::Detail::stringify(e0) == "0" );
-    Enum1 e1 = Enum1Value1;
-    CHECK( ::Catch::Detail::stringify(e1) == "1" );
-}
-
 // Enum with user-provided stream operator
 enum Enum2 { Enum2Value0, Enum2Value1 };
 
 std::ostream& operator<<( std::ostream& os, Enum2 v ) {
     return os << "E2{" << static_cast<int>(v) << "}";
 }
+} // end anonymous namespace
+
+TEST_CASE( "toString(enum)", "[toString][enum]" ) {
+    Enum1 e0 = Enum1Value0;
+    CHECK( ::Catch::Detail::stringify(e0) == "0" );
+    Enum1 e1 = Enum1Value1;
+    CHECK( ::Catch::Detail::stringify(e1) == "1" );
+}
 
 TEST_CASE( "toString(enum w/operator<<)", "[toString][enum]" ) {
     Enum2 e0 = Enum2Value0;
@@ -26,17 +28,11 @@ TEST_CASE( "toString(enum w/operator<<)", "[toString][enum]" ) {
 }
 
 // Enum class without user-provided stream operator
+namespace {
 enum class EnumClass1 { EnumClass1Value0, EnumClass1Value1 };
 
-TEST_CASE( "toString(enum class)", "[toString][enum][enumClass]" ) {
-    EnumClass1 e0 = EnumClass1::EnumClass1Value0;
-    CHECK( ::Catch::Detail::stringify(e0) == "0" );
-    EnumClass1 e1 = EnumClass1::EnumClass1Value1;
-    CHECK( ::Catch::Detail::stringify(e1) == "1" );
-}
-
 // Enum class with user-provided stream operator
-enum class EnumClass2 : short { EnumClass2Value0, EnumClass2Value1 };
+enum class EnumClass2 { EnumClass2Value0, EnumClass2Value1 };
 
 std::ostream& operator<<( std::ostream& os, EnumClass2 e2 ) {
     switch( static_cast<int>( e2 ) ) {
@@ -49,6 +45,16 @@ std::ostream& operator<<( std::ostream& os, EnumClass2 e2 ) {
     }
 }
 
+} // end anonymous namespace
+
+TEST_CASE( "toString(enum class)", "[toString][enum][enumClass]" ) {
+    EnumClass1 e0 = EnumClass1::EnumClass1Value0;
+    CHECK( ::Catch::Detail::stringify(e0) == "0" );
+    EnumClass1 e1 = EnumClass1::EnumClass1Value1;
+    CHECK( ::Catch::Detail::stringify(e1) == "1" );
+}
+
+
 TEST_CASE( "toString(enum class w/operator<<)", "[toString][enum][enumClass]" ) {
     EnumClass2 e0 = EnumClass2::EnumClass2Value0;
     CHECK( ::Catch::Detail::stringify(e0) == "E2/V0" );
@@ -58,4 +64,3 @@ TEST_CASE( "toString(enum class w/operator<<)", "[toString][enum][enumClass]" )
     EnumClass2 e3 = static_cast<EnumClass2>(10);
     CHECK( ::Catch::Detail::stringify(e3) == "Unknown enum value 10" );
 }
-

projects/SelfTest/UsageTests/ToStringGeneral.tests.cpp

@@ -116,6 +116,8 @@ TEST_CASE("Static arrays are convertible to string", "[toString]") {
     }
 }
 
+namespace {
+
 struct WhatException : std::exception {
     char const* what() const noexcept override {
         return "This exception has overriden what() method";
@@ -136,6 +138,8 @@ struct StringMakerException : std::exception {
     ~StringMakerException() override;
 };
 
+} // end anonymous namespace
+
 namespace Catch {
 template <>
 struct StringMaker<StringMakerException> {

projects/SelfTest/UsageTests/ToStringWhich.tests.cpp

@@ -16,6 +16,16 @@ std::string fallbackStringifier(T const&) {
 #include "catch.hpp"
 
 
+
+#if defined(__GNUC__)
+// This has to be left enabled until end of the TU, because the GCC
+// frontend reports operator<<(std::ostream& os, const has_maker_and_operator&)
+// as unused anyway
+#    pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+namespace {
+
 struct has_operator { };
 struct has_maker {};
 struct has_maker_and_operator {};
@@ -38,6 +48,8 @@ StreamT& operator<<(StreamT& os, const has_template_operator&) {
     return os;
 }
 
+} // end anonymous namespace
+
 namespace Catch {
     template<>
     struct StringMaker<has_maker> {
@@ -100,6 +112,8 @@ TEST_CASE( "stringify( vectors<has_maker_and_operator> )", "[toString]" ) {
     REQUIRE( ::Catch::Detail::stringify( v ) == "{ StringMaker<has_maker_and_operator> }" );
 }
 
+namespace {
+
 // Range-based conversion should only be used if other possibilities fail
 struct int_iterator {
     using iterator_category = std::input_iterator_tag;
@@ -139,6 +153,8 @@ struct stringmaker_range {
     int_iterator end() const { return {}; }
 };
 
+} // end anonymous namespace
+
 namespace Catch {
 template <>
 struct StringMaker<stringmaker_range> {
@@ -148,6 +164,8 @@ struct StringMaker<stringmaker_range> {
 };
 }
 
+namespace {
+
 struct just_range {
     int_iterator begin() const { return int_iterator{ 1 }; }
     int_iterator end() const { return {}; }
@@ -158,6 +176,8 @@ struct disabled_range {
     int_iterator end() const { return {}; }
 };
 
+} // end anonymous namespace
+
 namespace Catch {
 template <>
 struct is_range<disabled_range> {