# CheckIncludeFileCXX

Provides a macro to check if a header file can be included in `CXX`.

`CHECK_INCLUDE_FILE_CXX`

      CHECK_INCLUDE_FILE_CXX(<include> <variable> [<flags>])

  Check if the given `<include>` file may be included in a `CXX` source file and store the result in an internal cache entry named `<variable>`. The optional third argument may be used to add compilation flags to the check (or use `CMAKE_REQUIRED_FLAGS` below).

The following variables may be set before calling this macro to modify the way the check is run:

`CMAKE_REQUIRED_FLAGS`
  string of compile command line flags.
`CMAKE_REQUIRED_DEFINITIONS`
  a ;-list of macros to define (-DFOO=bar).
`CMAKE_REQUIRED_INCLUDES`
  a ;-list of header search paths to pass to the compiler.
`CMAKE_REQUIRED_LINK_OPTIONS`
  a ;-list of options to add to the link command.
`CMAKE_REQUIRED_LIBRARIES`
  a ;-list of libraries to add to the link command. See policy `CMP0075`.
`CMAKE_REQUIRED_QUIET`
  execute quietly without messages.

See modules `CheckIncludeFile` and `CheckIncludeFiles` to check for one or more `C` headers.