对于c ++，有没有相当于Python的'in'关键字？

Question

I'm trying to write my c++ code more clearly and compactly, so let's say I'm trying to avoid statements like:

if(MIN_VALUE <= a && a <= MAX_VALUE)

and replace it with something similar to:

if(a in [MIN_VALUE, MAX_VALUE])

Answer 1

You can use std::clamp which, unlike most STL functions, returns values in the closed interval [lo, hi] :

if (v == std::clamp(v, lo, hi)) {
    // lo <= v && v <= hi.
}

Answer 2

No there isn't but you could build one yourself:

template <typename T>
bool in(const T& a, const T& low, const T& high) 
{ 
    return a - low <= high - low; 
}