gcc warning about return value truncation

[Yubin Ruan <ablacktshirt@xxxxxxxxx>]

Is there any gcc flag to warn about this?

#include <iostream>
#include <cstdint>

int16_t func() {
    int32_t num = INT32_MAX;
    std::cout << "func() called " << num << std::endl;
    return num;
}

int main()
{
    int32_t val = func();
    std::cout << "return value is " << val << std::endl;
}

The return value of func() was truncated because the return type is
accidentally written as int16_t

Thanks,
Yubin