False positive missingReturn in uncompilable function

[ptomato]

bug.cpp:

#include <type_traits>
template<T>
bool f(T) {
    static_assert(std::is_arithmetic_v<T>);
    if constexpr (std::is_arithmetic_v<T>)
        return true;
}

Output:

$ cppcheck bug.cpp                                                                                                              
Checking bug.cpp ...
bug.cpp:6:0: error: Found a exit path from function with non-void return type that has missing return statement [missingReturn]
        return true;
^

If the static assertion fails, then the function should never be compiled, so I think it's a false positive that the return statement is missing.

Observed with cppcheck 2.6.

[Daniel Marjamäki]

I wonder.. It is not obvious to me why you have if constexpr (std::is_arithmetic_v<T>). Can it be changed to if constexpr (true) since a false condition will never be compiled?

[ptomato]

Hah, maybe I reduced the minimal example _too_ much :-)

How about this one?

#include <type_traits>
template<T>
bool f(T) {
    static_assert(std::is_arithmetic_v<T> || std::is_floating_point_v<T>);
    if constexpr (std::is_arithmetic_v<T>)
        return true;
    if constexpr (std::is_floating_point_v<T>)
        return false;
}

This way, the condition is not always true but there is no possible missingReturn.

[chrchr]

#11204 was closed as a duplicate.