find_package() has the flag REQUIRED. If it is set, the configuration fails when the package cannot be found.
I think this flag should be available for all find_* functions. This reduces duplicate code like
find_program(MYEXE myexe)
if(NOT MYEXE)
status(FATAL_ERROR "myexe has not been found")
endif()
Additionally, the variable <VAR>_FOUND should be set in each find_* function so the error handling code for is the same for optional find_program() and optional find_package().
What do you think?
