Ensure that M_PI is defined in any downstream compilation unit in Windows (#44)

Author: traversaro

angles/CMakeLists.txt

@@ -16,6 +16,9 @@ find_package(ament_cmake REQUIRED)
 add_library(angles INTERFACE)
 target_include_directories(angles INTERFACE
   "$<INSTALL_INTERFACE:include/angles>")
+if(WIN32)
+  target_compile_definitions(angles INTERFACE _USE_MATH_DEFINES)
+endif()
 
 if(BUILD_TESTING)
   find_package(ament_cmake_gtest REQUIRED)

angles/include/angles/angles.h

@@ -35,7 +35,10 @@
 #ifndef GEOMETRY_ANGLES_UTILS_H
 #define GEOMETRY_ANGLES_UTILS_H
 
+#ifndef _USE_MATH_DEFINES
 #define _USE_MATH_DEFINES
+#endif
+
 #include <algorithm>
 #include <cmath>