Function2 Versions Save

Full Changelog: https://github.com/Naios/function2/compare/4.2.2...4.2.3

Includes recent improvements

Includes minor maintainance and stability patches from the last year

• Fix reference types in the return type #35
• Add a workaround for a MSVC 16.3.1 compiler regression #29
• Propagate the empty state correctly into the erasure from function like types #27
• Fix an issue that owning unique functions were accidentally copyable #23
• Fix a typo in the function property #20
• And more minor improvements and code cleanups

• Improved CMake packaging it is now possible to:
  • Install function2 properly
  • Include a function2 subdirectory as subproject
• The minimum CMake version was raised to 3.11 because of issues with imported interface targets on lower versions.
• Interface breaking change: The capacity is now an integral_type like type rather than specifying the size directly, this makes it possible to also specify the alignment and it works better with capacities that shall hold a forward declared object which is defined later.

struct my_capacity {
  static constexpr std::size_t capacity = sizeof(my_type);
  static constexpr std::size_t alignment = alignof(my_type);
};

• [#16] Readme Wording
• [#15] Support and propagate noexcept-qualified function types
• [#14] Compilation error of fu2::unique_function having a capture
• [#13] Constructing function_view from fu2::function

• [a2b8cb0b2] Introduce the non owning function_view
• [4a3ff153af] Improvements to the size of the whole wrapper object
• [387f4938c] The object is now guaranteed to be allocated inplace if it fits into the internal buffer
• Many minor improvements

• #7
• #10
• Some minor improvements and warning fixes

This release fixes a major issue which lead to a double destruction when using the standard std::allocator