5 KiB
5 KiB
Nameof C++
_ _ __ _____
| \ | | / _| / ____|_ _
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| . ` |/ _` | '_ ` _ \ / _ \/ _ \| _| | | |_ _|_ _|
| |\ | (_| | | | | | | __/ (_) | | | |____|_| |_|
|_| \_|\__,_|_| |_| |_|\___|\___/|_| \_____|
What is Nameof?
Header-only C++17 library provides nameof macros and functions to obtain simple name of variable, type, function, macro, and enum.
Features
- C++17
- Header-only
- Dependency-free
- Compile-time
- Name of variable, member variable
- Name of type, variable type
- Name of function, member function
- Name of enum, enum variable
- Name of macro
- Enum to string
Examples
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Nameof
// Name of variable. NAMEOF(somevar) -> "somevar" // Name of member variable. NAMEOF(person.address.zip_code) -> "zip_code" // Name of function. NAMEOF(foo<int, float>()) -> "foo" // Name of member function. NAMEOF(somevar.some_method()) -> "some_method" NAMEOF(somevar.some_method<int>()) -> "some_method" // Name of macro. NAMEOF(__LINE__) -> "__LINE__" NAMEOF(NAMEOF(structvar)) -> "NAMEOF"
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Nameof enum
auto color = Color::RED; // Name of enum variable. NAMEOF_ENUM(color) -> "RED" nameof::nameof_enum(color) -> "RED"
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Nameof type
using T = int; T var = 42; // Name of variable type. NAMEOF_VAR_TYPE(var) -> "int" nameof::nameof_type<decltype(var)>() -> "int" // Name of type. NAMEOF_TYPE(T) -> "int" nameof::nameof_type<T>() -> "int"
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Compile-time
constexpr auto somevar_name = NAMEOF(somevar); // somevar_name -> "somevar" constexpr auto color_name = NAMEOF_ENUM(Color::BLUE); // or nameof::nameof_enum(Color::BLUE) // color_name -> "BLUE" constexpr auto var_type_name = NAMEOF_VAR_TYPE(var); // or nameof::nameof_type<decltype(var)>() // var_type_name -> "int" constexpr auto type_name = NAMEOF_VAR_TYPE(T); // or nameof::nameof_type<T>() // type_name -> "int"
Remarks
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Nameof returns
std::string_view
. If argument does not have name, returns empty string. -
Nameof expression argument are identified, but do not evaluated.
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Enum value must be in range
[-256, 256]
. If you need another range, add specialization enum_range for necessary enum type.#include <nameof.hpp> enum number { one = 100, two = 200, three = 300 }; namespace nameof { template <> struct enum_range<number> { static constexpr int min = 100; static constexpr int max = 300; }; }
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If you need name with template suffix, use NAMEOF_FULL.
// Name of function. NAMEOF_FULL(foo<int, float>()) -> "foo<int, float>" // Name of member function. NAMEOF_FULL(somevar.some_method<int>()) -> "some_method<int>"
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If you need raw fully-qualified name, use NAMEOF_RAW.
NAMEOF_RAW(somevar.somefield) -> "somevar.somefield" NAMEOF_RAW(&some_class::some_method<int>) -> "&some_class::some_method<int>"
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Spaces and Tabs ignored
NAMEOF( somevar ) -> "somevar" NAMEOF( somevar ) -> "somevar"
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Nameof enum obtains the first defined value enums, and won't work if value are aliased.
enum ShapeKind { ConvexBegin = 0, Box = 0, // Won't work. Sphere = 1, ConvexEnd = 2, Donut = 2, // Won't work too. Banana = 3, COUNT = 4, }; // NAMEOF_ENUM(ShapeKind::Box) -> "ConvexBegin" // nameof::nameof_enum(ShapeKind::Box) -> "ConvexBegin"
Work around the issue:
enum ShapeKind { // Convex shapes, see ConvexBegin and ConvexEnd below. Box = 0, Sphere = 1, // Non-convex shapes. Donut = 2, Banana = 3, COUNT = Banana + 1, // Non-reflected aliases. ConvexBegin = Box, ConvexEnd = Sphere + 1, }; // NAMEOF_ENUM(ShapeKind::Box) -> "Box" // nameof::nameof_enum(ShapeKind::Box) -> "Box" // Non-reflected aliases. // NAMEOF_ENUM(ShapeKind::ConvexBegin) -> "Box" // nameof::nameof_enum(ShapeKind::ConvexBegin) -> "Box"
Integration
You should add required file nameof.hpp.
Compiler compatibility
- Clang/LLVM >= 5
- Visual C++ >= 15.3 / Visual Studio >= 2017
- Xcode >= 9
- GCC >= 7 (GCC >= 9 for NAMEOF_ENUM)