Regroup find_package calls in top level CMakeLists.

CMakeLists.txt

@@ -18,6 +18,7 @@ include(CMakeDependentOption)
 option(MPL11_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
 option(MPL11_ENABLE_WERROR   "Fail and stop if a warning is triggered." OFF)
 option(MPL11_ENABLE_CXX0X    "Use the -std=c++0x switch if the compiler supports it." ON)
+option(MPL11_ENABLE_LIBCXX   "Use the -stdlib=libc++ if the compiler supports it." ON)
 CMAKE_DEPENDENT_OPTION(
     MPL11_ENABLE_TESTS "Enable the `unit` target. To avoid target name conflicts and cluttering the list of targets, unit tests are disabled when the library is nested inside another project."
     OFF "MPL11_IS_NESTED" # OFF when MPL11_IS_NESTED
@@ -39,8 +40,10 @@ CMAKE_DEPENDENT_OPTION(
 # Check available compiler flags
 #=============================================================================
 include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag(-ftemplate-backtrace-limit=0 MPL11_HAS_FTEMPLATE_BACKTRACE_LIMIT_0)
 check_cxx_compiler_flag(-pedantic                    MPL11_HAS_PEDANTIC_FLAG)
 check_cxx_compiler_flag(-std=c++0x                   MPL11_HAS_STDCXX0X_FLAG)
+check_cxx_compiler_flag(-stdlib=libc++               MPL11_HAS_STDLIB_LIBCXX_FLAG)
 check_cxx_compiler_flag(-W                           MPL11_HAS_W_FLAG)
 check_cxx_compiler_flag(-Wall                        MPL11_HAS_WALL_FLAG)
 check_cxx_compiler_flag(-Werror                      MPL11_HAS_WERROR_FLAG)
@@ -49,7 +52,6 @@ check_cxx_compiler_flag(-Wno-long-long               MPL11_HAS_WNO_LONG_LONG_FLA
 check_cxx_compiler_flag(-Wno-unused-local-typedefs   MPL11_HAS_WNO_UNUSED_LOCAL_TYPEDEFS_FLAG)
 check_cxx_compiler_flag(-Wno-unused-parameter        MPL11_HAS_WNO_UNUSED_PARAMETER_FLAG)
 check_cxx_compiler_flag(-Wwrite-strings              MPL11_HAS_WWRITE_STRINGS_FLAG)
-check_cxx_compiler_flag(-ftemplate-backtrace-limit=0 MPL11_HAS_FTEMPLATE_BACKTRACE_LIMIT_0)
 
 
 #=============================================================================
@@ -86,6 +88,10 @@ if (MPL11_ENABLE_CXX0X AND MPL11_HAS_STDCXX0X_FLAG)
     list(APPEND MPL11_CXX_FEATURE_FLAGS -std=c++0x)
 endif()
 
+if (MPL11_ENABLE_LIBCXX AND MPL11_HAS_STDLIB_LIBCXX_FLAG)
+    list(APPEND MPL11_CXX_FEATURE_FLAGS -stdlib=libc++)
+endif()
+
 # This is the only place where add_definitions is called. Other properties
 # are set on a per-target basis.
 add_definitions(
@@ -94,6 +100,18 @@ add_definitions(
 )
 
 
+#=============================================================================
+# Search for packages.
+#
+# Behavior when the package is found or not is customized at the
+# point where the package is required.
+#=============================================================================
+find_package(Boost)
+find_package(Doxygen)
+find_package(Gnuplot)
+find_package(Ruby 2)
+
+
 #=============================================================================
 # Setup the library
 #=============================================================================

doc/CMakeLists.txt

@@ -1,7 +1,6 @@
 #=============================================================================
 # Setup the documentation
 #=============================================================================
-find_package(Doxygen)
 if (DOXYGEN_FOUND)
     configure_file(Doxyfile.in Doxyfile @ONLY)
     add_custom_target(
@@ -10,5 +9,5 @@ if (DOXYGEN_FOUND)
         COMMENT "Generating API documentation with Doxygen" VERBATIM
     )
 else()
-    message(STATUS "Doxygen not found, the 'doc' target will be unavailable.")
+    message(STATUS "Doxygen not found; the 'doc' target will be unavailable.")
 endif()

example/CMakeLists.txt

@@ -1,20 +1,9 @@
 #=============================================================================
 # Setup examples
 #=============================================================================
-add_custom_target(example COMMENT "Build all the examples.")
+add_custom_target(examples COMMENT "Build all the examples.")
 
 function(mpl11_add_example name sources)
     add_executable(${name} ${sources})
-    add_dependencies(example ${name})
+    add_dependencies(examples ${name})
 endfunction()
-
-
-#=============================================================================
-# Setup examples requiring Boost
-#=============================================================================
-find_package(Boost QUIET)
-if (NOT Boost_FOUND)
-    message(STATUS "Boost headers were not found. Some examples won't be available.")
-else()
-
-endif()