Minimal updates (just the include guards) so Git is hopefully able to
detect the rename and track the history properly.
Everything except Magnum::GL doesn't compile now.
And removing the bundled std::optional implementation. This finally
makes this library compatible with C++17. Since this would be a huge
backwards-incompatible change that would make everyone angry, the
following had to be done in case both CORRADE_BUILD_DEPRECATED and
MAGNUM_BUILD_DEPRECATED is defined:
* Under C++11 and C++14, Containers::Optional / Containers::NullOpt is
aliased to std::optional / std::nullopt. This is no worse than the
state before, when we also provided these symbols.
* Under C++17, where standard <optional> header is available,
Containers::Optional provides implicit conversion to it. Only one-way
conversion is supported, as there was fortunately no Magnum API that
took std::optional via parameter, and there might be some corner
cases that this doesn't cover. The goal is to have all examples
compiling with the old API, at least.
* There's a new test especially for this, which checks that both the
C++11 and C++17 ways of doing things work as they should.
The typedef and conversion is marked as deprecated, so it will spit out
many warnings to push users to upgrade. I hope I can completely remove
this mess soon :/
Everything what was in src/ is now in src/Corrade, everything from
src/Plugins is now in src/MagnumPlugins, everything from external/ is in
src/MagnumExternal. Added new CMakeLists.txt file and updated the other
ones for the moves, no other change was made. If MAGNUM_BUILD_DEPRECATED
is set, everything compiles and installs like previously except for the
plugins, which are now in MagnumPlugins and not in Magnum/Plugins.
Moved them to `OpenGL/` subdirectory, allowing them to be included
explicitly with e.g. <OpenGL/GLES2/gl2ext.h> overriding the system
<GLES2/gl2ext.h> header. Our versions of the headers are thus now
explicitly included in `OpenGL.h`, but they can be also included using
no-prefix path if no system version is available. It might break some ES
platforms, they will be fixed when found.
The headers are now installed into `Magnum/OpenGL` (not into any
artificial `external` directory). Now also installing GLES2 headers for
OpenGL ES 2 (previously ES3 headers were installed for both ES2 and
ES3).
Vladimír Vondruš