Demangle type name generated by gcc, and test various string prefix.

gcc-demangle-type-name-string-types.cpp

#include <iostream>
#include <iomanip>
#include <typeinfo>
#include <cxxabi.h>

static char *getDemangledName(const char *mangledName) {
    int status;
    return abi::__cxa_demangle(mangledName, 0, 0, &status);
}

int main() {
#define OUT(t) { \
    char * demangled = getDemangledName(typeid(t).name()); \
    std::cout << std::left << std::setw(12) << #t \
    << std::setw(16) << demangled \
    << "\tsize = " << sizeof(t) << std::endl; \
    free(demangled); }

#define STR_(prefix) prefix ## "中文World"
#define STR(prefix) STR_(prefix)

#define TEST_(prefix, type) { auto prefix = STR(prefix); OUT(prefix); \
    type arr_##prefix[] = STR(prefix); OUT(arr_##prefix); }
#define TEST(prefix, type) TEST_(prefix, type)

    TEST(u8, const char);
    TEST(u, const char16_t);
    TEST(U, const char32_t);
    TEST(L, const wchar_t);

    return 0;
}

stdout.txt

u8          char const*     	size = 8
arr_u8      char [12]       	size = 12
u           char16_t const* 	size = 8
arr_u       char16_t [8]    	size = 16
U           char32_t const* 	size = 8
arr_U       char32_t [8]    	size = 32
L           wchar_t const*  	size = 8
arr_L       wchar_t [8]     	size = 32