I feel more confortable doing changes in a code that I do not know by
having some unit tests around it. These characterisation tests will
also be useful as documentation.
- templated structs were not required, SFINAE works for functions too
=> use instead, removes some unneeded code
- fix non-usage of builtins with clang
- adjust unit tests
errno can be set to a non-zero value from a previously failed system
call, it is not reset by successful ones
=> have to do that manually or the unit test fails because it detects
an "outdated" error message
This change define explicitly the behavior that exiv2::getEnv should have
on response to unexpected inputs.
There are some other minor changes:
- Use _putenv_s for the unit tests on Windows
- Add todo comment
- Remove deprecated note about freeing memory
I tried to use directly the private OBJECT library (exiv2lib_int) in the unit_tests targets, but the private objects have dependencies on the public symbols (circular dependency)
and therefore it is impossible to test the private code with that approach with the current design of the library.
Starting from CMake 3.3 we can use the variable CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS to export all the symbols of a shared library:
https://blog.kitware.com/create-dlls-on-windows-without-declspec-using-new-cmake-export-all-feature/
Even having the opportunity to use this variable (that will be only used when EXIV2_BUILD_UNIT_TESTS is enabled) the previous commits are still valid.
It is interesting to clearly differentiate between the public and private code of the library. Enforcing this, make us think twice before putting code in the public
part of the library.
