Tracing type instantiation / declaration location

test.cpp

#include <iostream>
#include <sstream>
#include <cmath>
#include <typeinfo>


#define TRACEABLE_DECLARATION static constexpr int __line__ = __LINE__; static constexpr const char *__file__ = __FILE__; 
#ifdef __GNUG__
#include <cxxabi.h>
#include <memory>

// Helper function to demangle type names
std::string demangle(const char* name) {
    int status = -1;
    std::unique_ptr<char[], void(*)(void*)> res{
        abi::__cxa_demangle(name, nullptr, nullptr, &status),
        std::free
    };
    return (status == 0) ? res.get() : name;
}
#else
std::string demangle(const char* name) {
    return name;
}
#endif

template <typename T> std::string declaration_info() {
    std::stringstream ss;
    ss << demangle(typeid(T).name()) << " declared on line " << T::__line__ << " in file " << T::__file__;
    return ss.str();
}

// EXAMPLE USAGE

// Primary template definition
template <typename A,typename B>
class BinaryOps { 
public:
  TRACEABLE_DECLARATION;

  static int ceil_multiply(A a, B b) {
        return static_cast<int>(std::ceil(a) * std::ceil(b));
  }
    
};

template <>
class BinaryOps<int,int> {
public:
    TRACEABLE_DECLARATION;
    
    static int ceil_multiply(int a, int b) {
        return (a * b);
    }
};



template <typename OPS> 
void try_ops() {
    std::cout << "Ceil multiplication result: of 3.2 and 4.2 = " << OPS::ceil_multiply(3.3, 4.2) << " type used to perform ceil multiply: " << declaration_info<OPS>() << std::endl;
}


int main() {
    try_ops<BinaryOps<int, int>>();
    try_ops<BinaryOps<float, float>>();
    try_ops<BinaryOps<float, int>>();

    
    return 0;
}

/*

Expected output:

Ceil multiplication result: of 3.2 and 4.2 = 12 type used to perform ceil multiply: BinaryOps<int, int> declared on line 50 in file /tmp/test.cpp
Ceil multiplication result: of 3.2 and 4.2 = 20 type used to perform ceil multiply: BinaryOps<float, float> declared on line 39 in file /tmp/test.cpp
Ceil multiplication result: of 3.2 and 4.2 = 16 type used to perform ceil multiply: BinaryOps<float, int> declared on line 39 in file /tmp/test.cpp

*/