Peter M. Groen / cxxopts

Fixes #276. Remove the fix for null dereference warning for GCC after
10.1.0 because this was removed in later versions.

Several clang-tidy improvements.

Workaround for GCC 10 null dereference warning.

Here is the warning currently being produced:

CMake Warning (dev) at C:/Program Files/CMake/share/cmake-3.19/Modules/GNUInstallDirs.cmake:223 (message):
Unable to determine default CMAKE_INSTALL_LIBDIR directory because no
target architecture is known. Please enable at least one language before
including GNUInstallDirs.
Call Stack (most recent call first):

I noted how I fixed the error. This is caused by GNUInstallDirs automatically executing code just by including it.

I also added -Werror=dev to the CI to ensure this never happens again.

Co-authored-by: Juan Ramos <juanr0911@gmail.com>

* Cmake Revamp

I needed to do a variety of things to ensure cxxopts worked well in my own project.

I created a new cmake module to abstract a lot of the logic in the main CMakelists.txt, I think it really assists in the readability of the project. Consequently a lot of logic is now written in functions.

I made a lot of the project options off by default unless the project is being built standalone. As a frequent consumer of cmake libraries this is a huge issue. Since examples, tests, installation, etc. aren't things I expect/desired by default when using libraries.

Co-authored-by: Juan Ramos <juanr0911@gmail.com>

Allow extra compiler warnings to be disabled.

We also add the suggested `override` keyword.

…ic flags are set (#238)

Makes some fixes to satisfy various strict warnings.

Fixes #257. The input array is not modified, so we can declare this as
`char const* const*`.

Major refactor of the parsing code organisation to improve encapsulation
and not modify the input arguments. The returned result no longer has
pointers into the original option specification.

* Fix compiler warning C4702  for MSVC-14

Fixes the installation paths by using cmake variables.

Adding support for the bazel build system

`cxxopts` doesn't modify the contents of the argv strings. This changes
the parse function to take a reference to a `const char**`.

Found with modernize-use-nodiscard

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* Fixes #245:

* Added a new exception type: `option_has_no_value_exception`; throwing it when an option has no value we can cast with `as()`, instead of an `std::domain_error`.
* The `OptionValue` type now holds a pointer to the long option name (in its corresponding key within ParseResults's `m_results` field.

…n on the command-line. (#247)

Uses std::exit instead of abort to terminate when exceptions are disabled.

Fixes #219. The example was wrong as ParseResult can't be returned out
of scope of the options parser.

Fixes #201. Parse char type correctly and check for length.

Fixes #202.

Fix CXXOPTS_NO_EXCEPTIONS so that it doesn't warn about unused parameters, and print out error messages.

Fixes #197. Don't parse default options twice when there is a short and
long option.

Install targets will not be generated if this option is set to OFF,
which is useful when including it as a bundled dependency of
another project.