std::thread::id formatter adapter (Twon#285)

* std::thread::id formatter adapter

libraries/core/src/morpheus/core/conversion/adapters/std/CMakeLists.txt

@@ -4,4 +4,5 @@ target_sources(MorpheusCore
         filesystem.hpp
         stacktrace.hpp
         source_location.hpp
+        thread.hpp
 )

libraries/core/src/morpheus/core/conversion/adapters/std/thread.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "morpheus/core/conformance/format.hpp"
+#include "morpheus/core/conformance/format.hpp"
+
+#include <thread>
+
+// clang-format off
+#if (__cpp_lib_formatters < 202302L)
+
+template <typename charT>
+struct morpheus::fmt_ns::formatter<std::thread::id, charT>
+{
+    constexpr auto parse(morpheus::fmt_ns::format_parse_context& ctx) { return std::begin(ctx); }
+
+    constexpr auto format(std::thread::id const& id, morpheus::fmt_ns::format_context& ctx) const
+    {
+#if MORPHEUS_IS_VISUALSTUDIO_COMPATIBLE_COMPILER
+        return morpheus::fmt_ns::format_to(ctx.out(), "{}", id._Get_underlying_id());
+#elif (MORPHEUS_COMPILER == MORPHEUS_APPLE_CLANG_COMPILER)
+        auto const idAsInt = *reinterpret_cast<std::uint64_t const*>(&id);
+        return morpheus::fmt_ns::format_to(ctx.out(), "{:#x}", idAsInt);
+#elif (MORPHEUS_IS_GCC_COMPATIBLE_COMPILER)
+        if constexpr (sizeof(id) == sizeof(std::uint64_t))
+        {
+            auto const idAsInt = *reinterpret_cast<std::uint64_t const*>(&id);
+            return morpheus::fmt_ns::format_to(ctx.out(), "{}", idAsInt);
+        }
+        else if constexpr (sizeof(id) == sizeof(std::uint32_t))
+        {
+            auto const idAsInt = *reinterpret_cast<std::uint32_t const*>(&id);
+            return morpheus::fmt_ns::format_to(ctx.out(), "{}", idAsInt);
+        }
+        else
+            static_assert(sizeof(id) == sizeof(std::uint32_t) || sizeof(id) == sizeof(std::uint64_t), "Expected size is 32 or 64-bits only. Extend support if required");
+#else
+    #error "Compiler unsupported for fallback std::formatter<std::thread::id> support"
+#endif // (MORPHEUS_COMPILER == MORPHEUS_VISUALSTUDIO_COMPILER)
+    }
+};
+
+#endif
+// clang-format on

libraries/core/tests/conformance/CMakeLists.txt

@@ -4,4 +4,5 @@ target_sources(MorpheusCoreTests
         print.tests.cpp
         scan.tests.cpp
         stacktrace.tests.cpp
+        thread.tests.cpp
 )

libraries/core/tests/conformance/stacktrace.tests.cpp

@@ -1,10 +1,8 @@
 #include "morpheus/core/conformance/stacktrace.hpp"
 #include "morpheus/core/conformance/format.hpp"
 #include "morpheus/core/conversion/adapters/std/stacktrace.hpp"
-#include "morpheus/temp_file.hpp"
 
 #include <catch2/catch_all.hpp>
-#include <iostream>
 
 namespace morpheus
 {

libraries/core/tests/conformance/thread.tests.cpp

@@ -0,0 +1,33 @@
+#include "morpheus/core/conformance/format.hpp"
+#include "morpheus/core/conversion/adapters/std/thread.hpp"
+#include "morpheus/temp_file.hpp"
+
+#include <catch2/catch_all.hpp>
+#include <thread>
+#include <sstream>
+
+namespace morpheus
+{
+
+TEST_CASE("Ensure std::thread::id format specialisation is supported and working", "[morpheus.conformance.thread]")
+{
+    GIVEN("a capture of the current stack trace")
+    {
+        auto const id = std::this_thread::get_id();
+
+        WHEN("Using std::format to write to a string")
+        {
+            // Ensure time zones work
+            auto const output = fmt_ns::format("{}", id);
+
+            THEN("Expect the variables wrote to the stream in the specified order")
+            {
+                std::stringstream str;
+                str << id;
+                REQUIRE(output == str.str());
+            }
+        }
+    }
+}
+
+}