How to Determine Class Name in C Without __CLASS__ Macro?

Determining Class Name in C

The absence of a direct equivalent to Python's __CLASS__ macro in C leaves developers seeking alternative solutions to retrieve the current class name during runtime.

To address this need, developers have devised macros that leverage various techniques to extract the class name from the information provided by the __PRETTY_FUNCTION__ macro. This macro, when used within a class method, returns a string representing the fully qualified method signature, including the class name, method name, and parameters.

One such macro, known as __METHOD_NAME__, utilizes the methodName helper function to parse the __PRETTY_FUNCTION__ string. It removes the return type, modifiers, and arguments, leaving only the class name and method name.

For example:

inline std::string methodName(const std::string& prettyFunction)
{
    size_t colons = prettyFunction.find("::");
    size_t begin = prettyFunction.substr(0,colons).rfind(" ") + 1;
    size_t end = prettyFunction.rfind("(") - begin;

    return prettyFunction.substr(begin,end) + "()";
}

#define __METHOD_NAME__ methodName(__PRETTY_FUNCTION__)

This macro allows developers to easily retrieve the class name in non-static methods. However, when used in static methods where the this pointer is not available, developers must consider alternative macros that utilize the __PRETTY_FUNCTION__ macro.

For scenarios where only the class name is required, the __CLASS_NAME__ macro can be employed:

inline std::string className(const std::string& prettyFunction)
{
    size_t colons = prettyFunction.find("::");
    if (colons == std::string::npos)
        return "::";
    size_t begin = prettyFunction.substr(0,colons).rfind(" ") + 1;
    size_t end = colons - begin;

    return prettyFunction.substr(begin,end);
}

#define __CLASS_NAME__ className(__PRETTY_FUNCTION__)

This macro caters to both class and static methods, parsing the __PRETTY_FUNCTION__ string to extract the class name effectively.

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