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+try_run
+-------
+
+Try compiling and then running some code.
+
+::
+
+  try_run(RUN_RESULT_VAR COMPILE_RESULT_VAR
+          bindir srcfile [CMAKE_FLAGS <Flags>]
+          [COMPILE_DEFINITIONS <flags>]
+          [COMPILE_OUTPUT_VARIABLE comp]
+          [RUN_OUTPUT_VARIABLE run]
+          [OUTPUT_VARIABLE var]
+          [ARGS <arg1> <arg2>...])
+
+Try compiling a srcfile.  Return TRUE or FALSE for success or failure
+in COMPILE_RESULT_VAR.  Then if the compile succeeded, run the
+executable and return its exit code in RUN_RESULT_VAR.  If the
+executable was built, but failed to run, then RUN_RESULT_VAR will be
+set to FAILED_TO_RUN.  COMPILE_OUTPUT_VARIABLE specifies the variable
+where the output from the compile step goes.  RUN_OUTPUT_VARIABLE
+specifies the variable where the output from the running executable
+goes.
+
+For compatibility reasons OUTPUT_VARIABLE is still supported, which
+gives you the output from the compile and run step combined.
+
+Cross compiling issues
+
+When cross compiling, the executable compiled in the first step
+usually cannot be run on the build host.  try_run() checks the
+CMAKE_CROSSCOMPILING variable to detect whether CMake is in
+crosscompiling mode.  If that's the case, it will still try to compile
+the executable, but it will not try to run the executable.  Instead it
+will create cache variables which must be filled by the user or by
+presetting them in some CMake script file to the values the executable
+would have produced if it had been run on its actual target platform.
+These variables are RUN_RESULT_VAR (explanation see above) and if
+RUN_OUTPUT_VARIABLE (or OUTPUT_VARIABLE) was used, an additional cache
+variable RUN_RESULT_VAR__COMPILE_RESULT_VAR__TRYRUN_OUTPUT.This is
+intended to hold stdout and stderr from the executable.
+
+In order to make cross compiling your project easier, use try_run only
+if really required.  If you use try_run, use RUN_OUTPUT_VARIABLE (or
+OUTPUT_VARIABLE) only if really required.  Using them will require
+that when crosscompiling, the cache variables will have to be set
+manually to the output of the executable.  You can also "guard" the
+calls to try_run with if(CMAKE_CROSSCOMPILING) and provide an
+easy-to-preset alternative for this case.
+
+Set variable CMAKE_TRY_COMPILE_CONFIGURATION to choose a build
+configuration.