Apply check functions to common functions

[yasahi-hpc]

Improves #80

This PR aims at replacing runtime assert with KOKKOSFFT_EXPECTS. Adding more static_assertions if applicable.
Modifications are applied to source code under common/src and common/unit_test.

Following modifications are made

• Apply are_valid_axes function where it is applicable
• Real to real case is suppressed by static_assertion in KokkosFFT_layout.hpp
• Apply KOKKOSFFT_EXPECTS to some if else conditional (throw std::runtime_error in the case of else)
• Replacing is_view<ViewType>::value with is_view_v<ViewType>

[tpadioleau]

Seems globally good to me!

Not directly related to his PR but I see you rely on the standard version to use std::source_location. I think it is more reliable to use feature testing like #if defined(__cpp_lib_source_location). This way you would be compatible with a compiler that supports only a part of C++ 20.

[yasahi-hpc]

Seems globally good to me!

Thank you for your reviews!

Not directly related to his PR but I see you rely on the standard version to use std::source_location. I think it is more reliable to use feature testing like #if defined(__cpp_lib_source_location). This way you would be compatible with a compiler that supports only a part of C++ 20.

I have fixed accordingly. My aims was to make sure that C++ 20 build actually relies on std::source_location rather than using C++17 version in case compiler does not support it.

[tpadioleau]

Good to me!