nameof() c++11

C++ alternative to nameof operator.

Linux/OSX	Windows

Used to obtain the simple name of a variable, type, function. 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.

A nameof expression has this form:

std::cout << NAMEOF(person.address.zip_code) << std::endl; // prints "zip_code"

Features

• Simple name
• C++11
• Header-only
• Dependency-free
• Compile-time
• Compilation check

Example & Key Use Cases

• Name of a variable, function and etc

NAMEOF(someVar) -> "someVar"
NAMEOF(someVar.SomeField) -> "SomeField"

NAMEOF(someVar.SomeMethod1()) -> "SomeMethod1()"
NAMEOF(&SomeStruct::SomeMethod2) -> "SomeMethod2"

• Name of enum

NAMEOF(SomeEnum::RED) -> "RED"
NAMEOF(SomeEnum::GREEN) -> "GREEN"

• Name of type

NAMEOF_TYPE(int[]) -> "int[]"
NAMEOF_TYPE(std::string) -> "string"

• Constexpr

void f() {
  int i;
  constexpr auto constexpr_work_fine = NAMEOF(i); -> "i"
}

• Compilation check

void f() {
  int i;
  NAMEOF(i); -> "i"
  NAMEOF(iii); -> error identifier "iii" is undefined
  NAMEOF_TYPE(std::stringgg) -> error namespace "std" has no member "stringgg"
}

• Validate parameters

void f(char* s) {
  if (s == nullptr)
    throw std::invalid_argument(NAMEOF(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

void f() {
  Log(NAMEOF(f), " method entry");
}

Remarks

If you need to get the fully-qualified name, you can use the NAMEOF_FULL(). For example:

NAMEOF_FULL(someVar.SomeField) -> "someVar.SomeField"
NAMEOF_FULL(&SomeStruct::SomeMethod2) -> "&SomeStruct::SomeMethod2"
NAMEOF_TYPE_FULL(std::string) -> "std::string"

License MIT