template関数を特定の型集合(浮動小数点型、整数型等)に特殊化する方法

たまに使うのに調べてもパッと出てこなかったので自分用のメモ

test.cc

#include <iostream>
#include <type_traits>

using std::cout;
using std::endl;

template <class T,
         typename std::enable_if<std::is_floating_point<T>::value, T>::type* = nullptr>
void func(T num){
    cout << "This is a floating point number:" << num << endl;
}
template <class T,
         typename std::enable_if<std::is_integral<T>::value, T>::type* = nullptr>
void func(T num){
    cout << "This is an integer number:" << num << endl;
}
template <class T,
         typename std::enable_if<!std::is_floating_point<T>::value && !std::is_integral<T>::value, T>::type* = nullptr>
void func(T num){
    cout << "This is neither integer nor floating number:" << num << endl;
}

int main(){
    func(123);
    func(123.);
    func(123.f);
    func("0x7B");
    return 0;
}