nameof_module/doc/limitations.md
2019-10-03 19:23:53 +05:00

2.5 KiB

Nameof

  • If argument does not have name, occurs the compilation error "Expression does not have a name.".

Nameof Type

  • To check is nameof type supported compiler use macro NAMEOF_TYPE_SUPPORTED or constexpr constant nameof::is_nameof_type_supported.

  • This library uses a compiler-specific hack (based on __PRETTY_FUNCTION__ / __FUNCSIG__), which works on Clang >= 5, MSVC >= 15.3 and GCC >= 7.

  • Nameof type returns compiler-specific type name.

  • If argument does not have name, occurs the compilation error "Expression does not have a name.".

Nameof Enum

  • To check is nameof enum supported compiler use macro NAMEOF_ENUM_SUPPORTED or constexpr constant nameof::is_nameof_enum_supported.

  • This library uses a compiler-specific hack (based on __PRETTY_FUNCTION__ / __FUNCSIG__), which works on Clang >= 5, MSVC >= 15.3 and GCC >= 9.

  • Enum can't reflect if the enum is a forward declaration.

  • Enum value must be in range [NAMEOF_ENUM_RANGE_MIN, NAMEOF_ENUM_RANGE_MAX]. By default NAMEOF_ENUM_RANGE_MIN = -128, NAMEOF_ENUM_RANGE_MAX = 128.

  • If need another range for all enum types by default, redefine the macro NAMEOF_ENUM_RANGE_MIN and NAMEOF_ENUM_RANGE_MAX.

    #define NAMEOF_ENUM_RANGE_MIN 0
    #define NAMEOF_ENUM_RANGE_MAX 256
    #include <nameof.hpp>
    
  • If need another range for specific enum type, 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;
    };
    }
    
  • 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::nameof_enum(ShapeKind::Box) -> "ConvexBegin"
    // 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::nameof_enum(ShapeKind::Box) -> "Box"
    // NAMEOF_ENUM(ShapeKind::Box) -> "Box"
    
    // Non-reflected aliases.
    // nameof::nameof_enum(ShapeKind::ConvexBegin) -> "Box"
    // NAMEOF_ENUM(ShapeKind::ConvexBegin) -> "Box"