NAME¶

std::type_info::name - std::type_info::name

Synopsis¶

const char* name() const; (until C++11)
const char* name() const noexcept; (since C++11)

Returns an implementation defined null-terminated character string containing the
name of the type. No guarantees are given; in particular, the returned string can be
identical for several types and change between invocations of the same program.

Parameters¶

(none)

Return value¶

Null-terminated character string containing the name of the type.

Notes¶

The lifetime of the array pointed to by the returned pointer is not specified, but
in practice it persists as long as the RTTI data structure for the given type
exists, which has application lifetime unless loaded from a dynamic library (that
can be unloaded).

Some implementations (such as MSVC, IBM, Oracle) produce a human-readable type name.
Others, most notably gcc and clang, return the mangled name, which is specified by
the Itanium C++ ABI. The mangled name can be converted to human-readable form using
implementation-specific API such as abi::__cxa_demangle directly or through
boost::core::demangle. It can also be piped through the command-line utility c++filt
-t.

Example¶

// Run this code

#include <boost/core/demangle.hpp>
#include <cstdlib>
#include <iostream>
#include <string>
#include <typeinfo>

struct Base { virtual ~Base() = default; };
struct Derived : Base {};

int main()
{
Base b1;
Derived d1;

const Base* pb = &b1;
std::cout << typeid(*pb).name() << '\n';
pb = &d1;
std::cout << typeid(*pb).name() << '\n';

std::string real_name = boost::core::demangle(typeid(pb).name());
std::cout << typeid(pb).name() << " => " << real_name << '\n';

std::cout << "c++filt => " << std::flush;
std::string s = typeid(pb).name();
std::system(("c++filt -t " + s).data());
}

Possible output:¶

// GCC/Clang:
4Base
7Derived
PK4Base => Base const*
c++filt => Base const*

// MSVC:
struct Base
struct Derived
struct Base const * __ptr64 => struct Base const * __ptr64

See also¶

hash_code returns a value which is identical for the same types
(C++11) (public member function)