Specialize output for all pointer types; fixes EQ w/ wchar_t* et al

appveyor.yml

@@ -30,7 +30,12 @@ environment:
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       TOOLSET: clang-win
       ADDRMD: 64
-      CXXSTD: 14,17,20,latest
+      CXXSTD: 14,17
+
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      TOOLSET: clang-win
+      ADDRMD: 64
+      CXXSTD: 20,latest
 
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
       ADDPATH: C:\cygwin\bin;

include/boost/core/lightweight_test.hpp

@@ -156,18 +156,15 @@ inline void no_throw_failed_impl(const char* expr, const char* what, const char*
 # pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
 
-// specialize test output for char pointers to avoid printing as cstring
-template <class T> inline const T& test_output_impl(const T& v) { return v; }
-inline const void* test_output_impl(const char* v) { return v; }
-inline const void* test_output_impl(const unsigned char* v) { return v; }
-inline const void* test_output_impl(const signed char* v) { return v; }
-inline const void* test_output_impl(char* v) { return v; }
-inline const void* test_output_impl(unsigned char* v) { return v; }
-inline const void* test_output_impl(signed char* v) { return v; }
-template<class T> inline const void* test_output_impl(T volatile* v) { return const_cast<T*>(v); }
+// specialize test output for pointers to avoid printing as cstring
+
+template<class T> inline T const& test_output_impl( T const& v ) { return v; }
+
+template<class T> inline void const* test_output_impl( T* const& v ) { return v; }
+template<class T> inline void const* test_output_impl( T volatile* const& v ) { return const_cast<T*>(v); }
 
 #if !defined( BOOST_NO_CXX11_NULLPTR )
-inline const void* test_output_impl(std::nullptr_t) { return nullptr; }
+inline const void* test_output_impl( std::nullptr_t ) { return nullptr; }
 #endif
 
 // print chars as numeric

test/Jamfile.v2

@@ -177,6 +177,9 @@ run lightweight_test_with_test.cpp
   : : : $(pedantic-errors) ;
 run-fail lightweight_test_with_fail.cpp ;
 
+run lightweight_test_eq_ptr.cpp
+  : : : $(pedantic-errors) ;
+
 run is_same_test.cpp ;
 
 run typeinfo_test.cpp ;

test/lightweight_test_eq_ptr.cpp

@@ -0,0 +1,106 @@
+// Copyright 2025 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+
+int main()
+{
+    {
+        char const* p = "12";
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        wchar_t const* p = L"12";
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+#if !defined( BOOST_NO_CXX11_CHAR16_T )
+
+    {
+        char16_t const* p = u"12";
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+#endif
+
+#if !defined( BOOST_NO_CXX11_CHAR32_T )
+
+    {
+        char32_t const* p = U"12";
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+#endif
+
+#if defined(__cpp_char8_t) && __cpp_char8_t >= 201811L
+
+    {
+        char8_t const* p = u8"12";
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+#endif
+
+    {
+        int v;
+        int volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        int v;
+        int const volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        char v;
+        char volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        char v;
+        char const volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        wchar_t v;
+        wchar_t volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    {
+        wchar_t v;
+        wchar_t const volatile* p = &v;
+
+        BOOST_TEST_EQ( p, p );
+        BOOST_TEST_NE( p, p + 1 );
+    }
+
+    return boost::report_errors();
+}