reflection Namespace

Reflection utilities for the µTest++ testing framework. More...

Definition

namespace micro_os_plus::micro_test_plus::reflection { ... }

Classes Index

class	source_location
	Local implementation of source location information for diagnostics. More...

Functions Index

template <class T>
constexpr std::string_view	type_name (void)
	Extracts the type name from the __PRETTY_FUNCTION__ identifier. More...
const char *	short_name (const char *name) noexcept
	Deprecated extraction of the file name from a path. More...

Description

Reflection utilities for the µTest++ testing framework.

The reflection namespace provides facilities for obtaining source location information and type names at compile time, for the reports of the checks.

It includes a local implementation of source_location for standard libraries that do not yet provide std::source_location, as well as a utility for extracting concise type names from the compiler-specific __PRETTY_FUNCTION__ identifier.

Functions

type_name()

template <class T>

std::string_view micro_os_plus::micro_test_plus::reflection::type_name (void)

nodiscard constexpr

Extracts the type name from the __PRETTY_FUNCTION__ identifier.

This function template parses the compiler-specific __PRETTY_FUNCTION__ identifier to extract a concise type name for the template parameter T.

Rather than relying on fixed character offsets (which are fragile across compiler versions and namespace changes), the implementation searches for the marker that introduces the template argument in the function signature string:

• Clang formats the signature as "... [T = <typename>]", so the type name lies between the first "[T = " and the last ']'. The marker is searched for as a whole, since the type name may itself contain brackets (e.g. int[3]).
• GCC formats the signature as "... [with T = <typename>]" or, on some versions, "... [with T = <typename>; ...]", so the type name starts after the first "[with T = " and ends at the following ';' or, if there is none, at the last ']'.

If the marker is not found, or the compiler is not supported (e.g. MSVC, which uses __FUNCSIG__ instead of __PRETTY_FUNCTION__), the function returns "unknown" rather than failing to compile, since the name is used only to improve the test output.

The expected layouts are verified at compile time by the static_assert checks that follow the definition.

The name is spelled as the compiler prints it, and is used to identify the expected exception type in the throws<E> failure messages. Only clang and GCC are supported; with other compilers the function returns "unknown".

Template Parameters

T	The type whose name is to be extracted.

Parameters

None.

Returns

A std::string_view containing the extracted type name, or "unknown" if it cannot be determined.

Definition at line 149 of file reflection-inlines.h.

149 type_name (void) -> std::string_view

150 {

151#if defined(__clang__)

152 // Clang: "... [T = <typename>]"

153 const std::string_view sv = __PRETTY_FUNCTION__;

154 constexpr std::string_view marker{ "[T = " };

155 const auto pos = sv.find (marker);

156 const auto end = sv.rfind (']');

157#elif defined(__GNUC__)

158 // GCC: "... [with T = <typename>]" or, on some versions,

159 // "... [with T = <typename>; std::string_view = ...]"

160 const std::string_view sv = __PRETTY_FUNCTION__;

161 constexpr std::string_view marker{ "[with T = " };

162 const auto pos = sv.find (marker);

163 const auto semi = sv.find (';', pos);

164 const auto end

165 = (semi != std::string_view::npos) ? semi : sv.rfind (']');

166#else

167 // Unsupported compiler; no portable signature string is available.

168 const std::string_view sv{};

169 constexpr std::string_view marker{};

170 const auto pos = std::string_view::npos;

171 const auto end = std::string_view::npos;

172#endif // defined(__clang__) || defined(__GNUC__)

173 if (pos == std::string_view::npos || end == std::string_view::npos

174 || end < pos + marker.size ())

175 {

176 return "unknown";

177 }

178 const auto start = pos + marker.size ();

179 return sv.substr (start, end - start);

180 }

Reference type_name.

Referenced by micro_os_plus::micro_test_plus::detail::expression_formatter::operator<< and type_name.

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The documentation for this namespace was generated from the following file:

• reflection-inlines.h

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