vec4: float& operator[](size_t index)

Return a reference to x if index is 0, a reference to y if index is 1, a reference to z if index is 2 or a reference to w if index is 3, else, throw an exception.

Example

#include "include/vec4.h"
#include <iostream>

int main() {
        nml::vec4 v(1.0f, 2.0f, 3.0f, 4.0f);
        v[0] = 3.0f;
        v[1] = 1.0f;
        v[2] = 4.0f;
        v[3] = 2.0f;
        std::cout << nml::to_string(v) << std::endl;
        v[4] = 5.0; // Error

        return 0;
}

Result:

[3.000000, 1.000000, 4.000000, 2.000000]
terminate called after throwing an instance of 'std::out_of_range'
        what():  vec4::operator[]: index is out of range.
Aborted