Added rapidjson.m4

cameo-api-cpp/m4/rapidjson.m4

+###############################################################################
+# Version 27/11/2019
+# defines RAPIDJSON_CFLAGS
+#
+AC_DEFUN([AC_RAPIDJSON],
+[ 
+  AC_ARG_WITH([rapidjson],
+         AS_HELP_STRING([--with-rapidjson=PREFIX],[Specify rapidjson library location]),
+         [],
+              [with_rapidjson=yes])
+
+    RAPIDJSON_CFLAGS=
+    if test $with_rapidjson != no; then
+        if test $with_rapidjson != yes; then
+            rapidjson_possible_path="$with_rapidjson"
+        else
+            rapidjson_possible_path="/usr/local /usr /opt /var"
+        fi
+        AC_MSG_CHECKING([for rapidjson headers])
+        rapidjson_save_CXXFLAGS="$CXXFLAGS"
+        rapidjson_found=no
+        for rapidjson_path_tmp in $rapidjson_possible_path ; do
+            # test include
+            CXXFLAGS="$CXXFLAGS -I$rapidjson_path_tmp/include"
+            AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <rapidjson/rapidjson.h>]],[[]])],
+                        [RAPIDJSON_CFLAGS="-I$rapidjson_path_tmp/include"
+                         rapidjson_found=yes]
+                        [])
+            CXXFLAGS="$rapidjson_save_CXXFLAGS"
+            if test $rapidjson_found = yes; then
+                break;
+            fi
+        done
+
+        AC_MSG_RESULT($rapidjson_found)
+        if test $rapidjson_found = yes; then
+            HAVE_RAPIDJSON=1
+            AC_MSG_RESULT(yes)
+            AC_SUBST(RAPIDJSON_CFLAGS)
+        else
+            AC_MSG_RESULT(no)
+        fi
+    fi
+])