3.9 KiB
3.9 KiB
Nameof C++
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Branch | Linux/OSX | Windows | License | Codacy |
---|---|---|---|---|
master |
Used to obtain the simple name of a variable, type, member, function, macros. Before, you had to use string literals to refer to definitions, which is brittle when renaming code elements because tools do not know to check these string literals.
Features
- C++17
- Header-only
- Dependency-free
- Compile-time
- Compilation check
- Name of variable
- Name of member
- Name of function
- Name of emum
- Name of macrose
- Name of type
Examples
- A nameof macros expression has this form
// Name of variable
NAMEOF(somevar) -> "somevar"
// Name of member
NAMEOF(person.address.zip_code) -> "zip_code"
// Name of function
NAMEOF(SomeMethod<int, float>) -> "SomeMethod"
NAMEOF_FULL(SomeMethod<int, float>) -> "SomeMethod4<int, float>"
// Name of enum
auto c = Color::RED;
NAMEOF_ENUM(c) -> "RED"
// Name of type
NAMEOF_TYPE(Color::RED) -> "Color"
NAMEOF_TYPE_T(int) -> "int"
// Name of macros
NAMEOF(__LINE__) -> "__LINE__"
- Constexpr
constexpr auto cx = NAMEOF(somevar); -> "somevar"
static_assert("somevar" == cx, "Wrong name!");
- Compilation check
NAMEOF_TYPE_T(std::stringgg) -> error namespace "std" has no member "stringgg"
- Validate parameters
void f(char* s) {
if (s == nullptr)
throw std::invalid_argument(NAMEOF(s).apend("with type = ").apend(NAMEOF_TYPE(s)));
}
- Serialization, for example json:
void to_json(json& j, const person& p) {
j = json{{NAMEOF(p.name), p.name},
{NAMEOF(p.address), p.address},
{NAMEOF(p.age), p.age}};
}
void from_json(const json& j, person& p) {
p.name = j.at(NAMEOF(p.name));
p.address = j.at(NAMEOF(p.address));
p.age = j.at(NAMEOF(p.age));
}
- Logging
template <typename T>
void f() {
Log(NAMEOF(f) + " method entry with T = " + NAMEOF_TYPE_T(T));
}
Remarks
-
Nameof return std::string_view.
-
The argument expression identifies a code definition, but it is never evaluated.
-
If you need raw fully-qualified name, use NAMEOF_RAW().
NAMEOF_RAW(somevar.somefield) -> "somevar.somefield"
NAMEOF_RAW(&SomeStruct::SomeMethod) -> "&SomeStruct::SomeMethod"
- Instead of macros NAMEOF_ENUM, you can use the function nameof::NameofEnum().
nameof::NameofEnum(Color::RED) -> "RED"
auto c = Color::RED;
nameof::NameofEnum(c) -> "RED"
- Instead of macros NAMEOF_TYPE, you can use the function nameof::NameofType<>.
nameof::NameofType(Color::RED) -> "Color"
nameof::NameofType<decltype(Color::RED)>() -> "Color"
nameof::NameofType<int> -> "int"
- NAMEOF_ENUM does not work on the GCC.
auto c = Color::RED;
NAMEOF_ENUM(c) -> "(Color)0"
- Spaces and Tabs ignored
NAMEOF( somevar ) -> "somevar"
NAMEOF( somevar ) -> "somevar"
Integration
You should add required file nameof.hpp.
Compiler compatibility
- GCC
- Clang
- MSVC