我喜欢Nick的方法，一个完整的表单可能是这样的(对于所有基本数据类型):

template <typename T> const char* typeof(T&) { return "unknown"; }    // default
template<> const char* typeof(int&) { return "int"; }
template<> const char* typeof(short&) { return "short"; }
template<> const char* typeof(long&) { return "long"; }
template<> const char* typeof(unsigned&) { return "unsigned"; }
template<> const char* typeof(unsigned short&) { return "unsigned short"; }
template<> const char* typeof(unsigned long&) { return "unsigned long"; }
template<> const char* typeof(float&) { return "float"; }
template<> const char* typeof(double&) { return "double"; }
template<> const char* typeof(long double&) { return "long double"; }
template<> const char* typeof(std::string&) { return "String"; }
template<> const char* typeof(char&) { return "char"; }
template<> const char* typeof(signed char&) { return "signed char"; }
template<> const char* typeof(unsigned char&) { return "unsigned char"; }
template<> const char* typeof(char*&) { return "char*"; }
template<> const char* typeof(signed char*&) { return "signed char*"; }
template<> const char* typeof(unsigned char*&) { return "unsigned char*"; }

对于一些不同的东西，这里有一个类型的“To English”转换，解构每个限定符、范围、参数等等，递归地构建描述类型的字符串，我认为“演绎这个”建议将有助于减少许多特殊化。无论如何，这是一个有趣的晨练，尽管过度膨胀。：）

struct X {
    using T = int *((*)[10]);
    T f(T, const unsigned long long * volatile * );
};

int main() {

    std::cout << describe<decltype(&X::f)>() << std::endl;
}

输出:

pointer to member function of class 1X taking (pointer to array[10]
of pointer to int, pointer to volatile pointer to const unsigned 
long long), and returning pointer to array[10] of pointer to int

代码如下: https://godbolt.org/z/7jKK4or43

注:最新版本在我的github: https://github.com/cuzdav/type_to_string

// Print types as strings, including functions, member 

#include <type_traits>
#include <typeinfo>
#include <string>
#include <utility>

namespace detail {

template <typename T> struct Describe;

template <typename T, class ClassT> 
struct Describe<T (ClassT::*)>  {
    static std::string describe();
};
template <typename RetT, typename... ArgsT> 
struct Describe<RetT(ArgsT...)>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...)>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...)&>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const &>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile &>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) & noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile &>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const & noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile & noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile & noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) &&>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const &&>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile &&>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) && noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile &&>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const && noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) volatile && noexcept>  {
    static std::string describe();
};
template <typename RetT, class ClassT, typename... ArgsT> 
struct Describe<RetT(ClassT::*)(ArgsT...) const volatile && noexcept>  {
    static std::string describe();
};

template <typename T>
std::string describe()
{
    using namespace std::string_literals;
    auto terminal = [&](char const * desc) {
        return desc + " "s + typeid(T).name();
    };
    if constexpr(std::is_const_v<T>) {
        return "const " + describe<std::remove_const_t<T>>();
    }
    else if constexpr(std::is_volatile_v<T>) {
        return "volatile " + describe<std::remove_volatile_t<T>>();
    }
    else if constexpr (std::is_same_v<bool, T>) {
        return "bool";
    }
    else if constexpr(std::is_same_v<char, T>) {
        return "char";
    }
    else if constexpr(std::is_same_v<signed char, T>) {
        return "signed char";
    }
    else if constexpr(std::is_same_v<unsigned char, T>) {
        return "unsigned char";
    }
    else if constexpr(std::is_unsigned_v<T>) {
        return "unsigned " + describe<std::make_signed_t<T>>();
    }
    else if constexpr(std::is_void_v<T>) {
        return "void";
    }
    else if constexpr(std::is_integral_v<T>) {
        if constexpr(std::is_same_v<short, T>) 
            return "short";
        else if constexpr(std::is_same_v<int, T>) 
            return "int";
        else if constexpr(std::is_same_v<long, T>) 
            return "long";
        else if constexpr(std::is_same_v<long long, T>) 
            return "long long";
    }
    else if constexpr(std::is_same_v<float, T>) {
        return "float";
    }
    else if constexpr(std::is_same_v<double, T>) {
        return "double";
    }
    else if constexpr(std::is_same_v<long double, T>) {
        return "long double";
    }
    else if constexpr(std::is_same_v<std::nullptr_t, T>) { 
        return "nullptr_t";
    }
    else if constexpr(std::is_class_v<T>) {
        return terminal("class");
    }
    else if constexpr(std::is_union_v<T>) {
        return terminal("union");
    }
    else if constexpr(std::is_enum_v<T>) {
        std::string result;
        if (!std::is_convertible_v<T, std::underlying_type_t<T>>) {
            result += "scoped ";
        }
        return result + terminal("enum");
    }  
    else if constexpr(std::is_pointer_v<T>) {
        return "pointer to " + describe<std::remove_pointer_t<T>>();
    }
    else if constexpr(std::is_lvalue_reference_v<T>) {
        return "lvalue-ref to " + describe<std::remove_reference_t<T>>();
    }
    else if constexpr(std::is_rvalue_reference_v<T>) {
        return "rvalue-ref to " + describe<std::remove_reference_t<T>>();
    }
    else if constexpr(std::is_bounded_array_v<T>) {
        return "array[" + std::to_string(std::extent_v<T>) + "] of " +
            describe<std::remove_extent_t<T>>();
    }
    else if constexpr(std::is_unbounded_array_v<T>) {
        return "array[] of " + describe<std::remove_extent_t<T>>();
    }
    else if constexpr(std::is_function_v<T>) {
        return Describe<T>::describe();
    }
    else if constexpr(std::is_member_object_pointer_v<T>) {
        return Describe<T>::describe();
    }
    else if constexpr(std::is_member_function_pointer_v<T>) {
        return Describe<T>::describe();
    }
}

template <typename RetT, typename... ArgsT> 
std::string Describe<RetT(ArgsT...)>::describe() {
    std::string result = "function taking (";
    ((result += detail::describe<ArgsT>(", ")), ...);
    return result + "), returning " + detail::describe<RetT>();
}

template <typename T, class ClassT> 
std::string Describe<T (ClassT::*)>::describe() {
    return "pointer to member of " + detail::describe<ClassT>() +
        " of type " + detail::describe<T>();
}

struct Comma {
    char const * sep = "";
    std::string operator()(std::string const& str) {
        return std::exchange(sep, ", ") + str;
    }
};
enum Qualifiers {NONE=0, CONST=1, VOLATILE=2, NOEXCEPT=4, LVREF=8, RVREF=16};

template <typename RetT, typename ClassT, typename... ArgsT>
std::string describeMemberPointer(Qualifiers q) {
    std::string result = "pointer to ";
    if (NONE != (q & CONST)) result += "const ";
    if (NONE != (q & VOLATILE)) result += "volatile ";
    if (NONE != (q & NOEXCEPT)) result += "noexcept ";
    if (NONE != (q & LVREF)) result += "lvalue-ref ";
    if (NONE != (q & RVREF)) result += "rvalue-ref ";
    result += "member function of " + detail::describe<ClassT>() + " taking (";
    Comma comma;
    ((result += comma(detail::describe<ArgsT>())), ...);
    return result + "), and returning " + detail::describe<RetT>();
}

template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...)>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(NONE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(CONST);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(VOLATILE | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(CONST | VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(CONST | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(CONST | VOLATILE | NOEXCEPT);
}

template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) &>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const &>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | CONST);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) & noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile &>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile & noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | VOLATILE | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile &>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | CONST | VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const & noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | CONST | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile & noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(LVREF | CONST | VOLATILE | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...)&&>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const &&>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | CONST);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) && noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile &&>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) volatile && noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | VOLATILE | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile &&>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | CONST | VOLATILE);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const && noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | CONST | NOEXCEPT);
}
template <typename RetT, class ClassT, typename... ArgsT> 
std::string Describe<RetT(ClassT::*)(ArgsT...) const volatile && noexcept>::describe() {
    return describeMemberPointer<RetT, ClassT, ArgsT...>(RVREF | CONST | VOLATILE | NOEXCEPT);
}

} // detail

///////////////////////////////////
// Main function
///////////////////////////////////
template <typename T>
std::string describe() {
    return detail::describe<T>();
}


///////////////////////////////////
// Sample code
///////////////////////////////////
#include <iostream>


struct X {
    using T = int *((*)[10]);
    T f(T, const unsigned long long * volatile * );
};

int main() {
    std::cout << describe<decltype(&X::f)>() << std::endl;
}

#include <iostream>
#include <typeinfo>
using namespace std;
#define show_type_name(_t) \
    system(("echo " + string(typeid(_t).name()) + " | c++filt -t").c_str())

int main() {
    auto a = {"one", "two", "three"};
    cout << "Type of a: " << typeid(a).name() << endl;
    cout << "Real type of a:\n";
    show_type_name(a);
    for (auto s : a) {
        if (string(s) == "one") {
            cout << "Type of s: " << typeid(s).name() << endl;
            cout << "Real type of s:\n";
            show_type_name(s);
        }
        cout << s << endl;
    }

    int i = 5;
    cout << "Type of i: " << typeid(i).name() << endl;
    cout << "Real type of i:\n";
    show_type_name(i);
    return 0;
}

输出:

Type of a: St16initializer_listIPKcE
Real type of a:
std::initializer_list<char const*>
Type of s: PKc
Real type of s:
char const*
one
two
three
Type of i: i
Real type of i:
int

c++ 11更新到一个非常老的问题:在c++中打印变量类型。

公认的(好的)答案是使用typeid(a).name()，其中a是变量名。

现在在c++ 11中，我们有了decltype(x)，它可以将表达式转换为类型。decltype()有自己的一组非常有趣的规则。例如，decltype(a)和decltype((a))通常是不同的类型(一旦这些原因暴露出来，就会出现良好且可理解的原因)。

我们可信的类型id(a).name()能帮助我们探索这个美丽的新世界吗?

No.

但是这个工具并不复杂。我就是用这个工具来回答这个问题的。我将比较这个新工具与typeid(a).name()。这个新工具实际上构建在typeid(a).name()之上。

根本问题是:

typeid(a).name()

丢弃cv限定符、引用和左值/右值。例如:

const int ci = 0;
std::cout << typeid(ci).name() << '\n';

对于我输出:

i

我猜MSVC的输出:

int

即const消失了。这不是QOI(实施质量)问题。标准要求这种行为。

以下是我的建议:

template <typename T> std::string type_name();

可以这样使用:

const int ci = 0;
std::cout << type_name<decltype(ci)>() << '\n';

对我来说输出:

int const

我还没有在MSVC上测试过这个。但是我欢迎那些喜欢的人给我反馈。

c++ 11解决方案

我对非msvc平台使用__cxa_demangle，这是ipapadop在他对demangle类型的回答中推荐的。但是在MSVC上，我相信typeid需要名称(未经测试)。这个核心包含一些简单的测试，用于检测、恢复和报告cv限定符和对输入类型的引用。

#include <type_traits>
#include <typeinfo>
#ifndef _MSC_VER
#   include <cxxabi.h>
#endif
#include <memory>
#include <string>
#include <cstdlib>

template <class T>
std::string
type_name()
{
    typedef typename std::remove_reference<T>::type TR;
    std::unique_ptr<char, void(*)(void*)> own
           (
#ifndef _MSC_VER
                abi::__cxa_demangle(typeid(TR).name(), nullptr,
                                           nullptr, nullptr),
#else
                nullptr,
#endif
                std::free
           );
    std::string r = own != nullptr ? own.get() : typeid(TR).name();
    if (std::is_const<TR>::value)
        r += " const";
    if (std::is_volatile<TR>::value)
        r += " volatile";
    if (std::is_lvalue_reference<T>::value)
        r += "&";
    else if (std::is_rvalue_reference<T>::value)
        r += "&&";
    return r;
}

结果

有了这个解决方案，我可以这样做:

int& foo_lref();
int&& foo_rref();
int foo_value();

int
main()
{
    int i = 0;
    const int ci = 0;
    std::cout << "decltype(i) is " << type_name<decltype(i)>() << '\n';
    std::cout << "decltype((i)) is " << type_name<decltype((i))>() << '\n';
    std::cout << "decltype(ci) is " << type_name<decltype(ci)>() << '\n';
    std::cout << "decltype((ci)) is " << type_name<decltype((ci))>() << '\n';
    std::cout << "decltype(static_cast<int&>(i)) is " << type_name<decltype(static_cast<int&>(i))>() << '\n';
    std::cout << "decltype(static_cast<int&&>(i)) is " << type_name<decltype(static_cast<int&&>(i))>() << '\n';
    std::cout << "decltype(static_cast<int>(i)) is " << type_name<decltype(static_cast<int>(i))>() << '\n';
    std::cout << "decltype(foo_lref()) is " << type_name<decltype(foo_lref())>() << '\n';
    std::cout << "decltype(foo_rref()) is " << type_name<decltype(foo_rref())>() << '\n';
    std::cout << "decltype(foo_value()) is " << type_name<decltype(foo_value())>() << '\n';
}

输出为:

decltype(i) is int
decltype((i)) is int&
decltype(ci) is int const
decltype((ci)) is int const&
decltype(static_cast<int&>(i)) is int&
decltype(static_cast<int&&>(i)) is int&&
decltype(static_cast<int>(i)) is int
decltype(foo_lref()) is int&
decltype(foo_rref()) is int&&
decltype(foo_value()) is int

注意(例如)decltype(i)和decltype((i))之间的区别。前者是i声明的类型，后者是表达式i的“类型”(表达式从来没有引用类型，但按照惯例，decltype表示带有左值引用的左值表达式)。

因此，除了探索和调试自己的代码之外，这个工具还是学习decltype的绝佳工具。

相比之下，如果我只是在typeid(a).name()上构建这个，而不添加回丢失的cv-qualifiers或引用，输出将是:

decltype(i) is int
decltype((i)) is int
decltype(ci) is int
decltype((ci)) is int
decltype(static_cast<int&>(i)) is int
decltype(static_cast<int&&>(i)) is int
decltype(static_cast<int>(i)) is int
decltype(foo_lref()) is int
decltype(foo_rref()) is int
decltype(foo_value()) is int

也就是说，所有的引用和简历修饰符都被剥离了。

c++ 14更新

就在你认为自己已经找到了解决问题的办法时，总会有人不知从哪里冒出来，给你展示一个更好的方法。: -)

这个来自Jamboree的回答展示了如何在编译时在c++ 14中获取类型名。这是一个出色的解决方案，原因如下:

它在编译时! 你让编译器本身来做这项工作，而不是一个库(甚至是std::lib)。这意味着对于最新的语言特性(如lambdas)会得到更准确的结果。

Jamboree的答案并没有完全为VS铺开一切，我稍微调整了一下他的代码。但由于这个答案获得了很多点击量，花点时间去那里为他的答案投票，如果没有投票，这个更新就不会发生。

#include <cstddef>
#include <stdexcept>
#include <cstring>
#include <ostream>

#ifndef _MSC_VER
#  if __cplusplus < 201103
#    define CONSTEXPR11_TN
#    define CONSTEXPR14_TN
#    define NOEXCEPT_TN
#  elif __cplusplus < 201402
#    define CONSTEXPR11_TN constexpr
#    define CONSTEXPR14_TN
#    define NOEXCEPT_TN noexcept
#  else
#    define CONSTEXPR11_TN constexpr
#    define CONSTEXPR14_TN constexpr
#    define NOEXCEPT_TN noexcept
#  endif
#else  // _MSC_VER
#  if _MSC_VER < 1900
#    define CONSTEXPR11_TN
#    define CONSTEXPR14_TN
#    define NOEXCEPT_TN
#  elif _MSC_VER < 2000
#    define CONSTEXPR11_TN constexpr
#    define CONSTEXPR14_TN
#    define NOEXCEPT_TN noexcept
#  else
#    define CONSTEXPR11_TN constexpr
#    define CONSTEXPR14_TN constexpr
#    define NOEXCEPT_TN noexcept
#  endif
#endif  // _MSC_VER

class static_string
{
    const char* const p_;
    const std::size_t sz_;

public:
    typedef const char* const_iterator;

    template <std::size_t N>
    CONSTEXPR11_TN static_string(const char(&a)[N]) NOEXCEPT_TN
        : p_(a)
        , sz_(N-1)
        {}

    CONSTEXPR11_TN static_string(const char* p, std::size_t N) NOEXCEPT_TN
        : p_(p)
        , sz_(N)
        {}

    CONSTEXPR11_TN const char* data() const NOEXCEPT_TN {return p_;}
    CONSTEXPR11_TN std::size_t size() const NOEXCEPT_TN {return sz_;}

    CONSTEXPR11_TN const_iterator begin() const NOEXCEPT_TN {return p_;}
    CONSTEXPR11_TN const_iterator end()   const NOEXCEPT_TN {return p_ + sz_;}

    CONSTEXPR11_TN char operator[](std::size_t n) const
    {
        return n < sz_ ? p_[n] : throw std::out_of_range("static_string");
    }
};

inline
std::ostream&
operator<<(std::ostream& os, static_string const& s)
{
    return os.write(s.data(), s.size());
}

template <class T>
CONSTEXPR14_TN
static_string
type_name()
{
#ifdef __clang__
    static_string p = __PRETTY_FUNCTION__;
    return static_string(p.data() + 31, p.size() - 31 - 1);
#elif defined(__GNUC__)
    static_string p = __PRETTY_FUNCTION__;
#  if __cplusplus < 201402
    return static_string(p.data() + 36, p.size() - 36 - 1);
#  else
    return static_string(p.data() + 46, p.size() - 46 - 1);
#  endif
#elif defined(_MSC_VER)
    static_string p = __FUNCSIG__;
    return static_string(p.data() + 38, p.size() - 38 - 7);
#endif
}

如果你仍然停留在古老的c++ 11中，这段代码将在constexpr上自动后退。如果你用c++ 98/03在洞穴墙壁上作画，noexcept也会被牺牲掉。

c++ 17更新

在下面的评论中，Lyberta指出新的std::string_view可以取代static_string:

template <class T>
constexpr
std::string_view
type_name()
{
    using namespace std;
#ifdef __clang__
    string_view p = __PRETTY_FUNCTION__;
    return string_view(p.data() + 34, p.size() - 34 - 1);
#elif defined(__GNUC__)
    string_view p = __PRETTY_FUNCTION__;
#  if __cplusplus < 201402
    return string_view(p.data() + 36, p.size() - 36 - 1);
#  else
    return string_view(p.data() + 49, p.find(';', 49) - 49);
#  endif
#elif defined(_MSC_VER)
    string_view p = __FUNCSIG__;
    return string_view(p.data() + 84, p.size() - 84 - 7);
#endif
}

我已经更新了VS的常数，这要感谢Jive Dadson在下面的评论中非常好的侦探工作。

更新:

一定要看看这个重写或下面这个重写，它消除了我最新公式中不可读的神奇数字。

一个没有函数重载的更通用的解决方案:

template<typename T>
std::string TypeOf(T){
    std::string Type="unknown";
    if(std::is_same<T,int>::value) Type="int";
    if(std::is_same<T,std::string>::value) Type="String";
    if(std::is_same<T,MyClass>::value) Type="MyClass";

    return Type;}

这里的MyClass是用户定义的类。这里还可以添加更多的条件。

例子:

#include <iostream>



class MyClass{};


template<typename T>
std::string TypeOf(T){
    std::string Type="unknown";
    if(std::is_same<T,int>::value) Type="int";
    if(std::is_same<T,std::string>::value) Type="String";
    if(std::is_same<T,MyClass>::value) Type="MyClass";
    return Type;}


int main(){;
    int a=0;
    std::string s="";
    MyClass my;
    std::cout<<TypeOf(a)<<std::endl;
    std::cout<<TypeOf(s)<<std::endl;
    std::cout<<TypeOf(my)<<std::endl;

    return 0;}

输出:

int
String
MyClass

正如Scott Meyers在《Effective Modern c++》中所解释的那样，

对std::type_info::name的调用不能保证返回任何有意义的东西。

最好的解决方案是让编译器在类型推断期间生成错误消息，例如:

template<typename T>
class TD;

int main(){
    const int theAnswer = 32;
    auto x = theAnswer;
    auto y = &theAnswer;
    TD<decltype(x)> xType;
    TD<decltype(y)> yType;
    return 0;
}

根据不同的编译器，结果会是这样的:

test4.cpp:10:21: error: aggregate ‘TD<int> xType’ has incomplete type and cannot be defined TD<decltype(x)> xType;

test4.cpp:11:21: error: aggregate ‘TD<const int *> yType’ has incomplete type and cannot be defined TD<decltype(y)> yType;

因此，我们知道x的类型是int, y的类型是const int*