C ++：模板类专门化和类型特征

Question

My problem is the following

template<class T> MyClass
{
    MyClass(/* Lots of parameters with no problem */, const T& min = 0, const T& max = std::numeric_limits<T>::max());
    set(/* Lots of parameters with no problem */, const T& min = 0, const T& max = std::numeric_limits<T>::max());
    /* Lots of function with no problem */
}

I want my template class to be compatible with std::string without reimplementing all the functions. For std::string I want min = "" and max = "" . Currently, it crashes as 0 for example cannot be converted to a string. How to do that ? (if I can specialize only the constructor and the main setter it would be great).

Answer 1

Create the wrapper I guess? :

template<typename T> struct ttraits
{
static T max(){
return std::numeric_limits<T>::max();
}
static T min(){
return std::numeric_limits<T>::min();
}
};

template<> struct ttraits<std::string>
{
static std::string max(){
return ""; //or whatever max is for you
}
static std::string min(){
return "";
}

Answer 2

You can always select the right overload for something to handle special cases with enable_if or you can think better about how to make your code more robust. Using 0 to initialize a template parameter is not a good idea, while T() is.

Answer 3

制作自己的numeric_limits ，该值将重定向到标准值并专门用于字符串。

Answer 4

set(T & const p_Arg = Initializer<T>())

其中Initializer专用于所有受支持的类型。