fix review findings.

include/assimp/StringUtils.h

@@ -42,6 +42,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef INCLUDED_AI_STRINGUTILS_H
 #define INCLUDED_AI_STRINGUTILS_H
 
+#include <assimp/defs.h>
+
 #include <sstream>
 #include <stdarg.h>
 #include <cstdlib>
@@ -55,7 +57,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ///	@return	The number of written characters if the buffer size was big enough. If an encoding error occurs, a negative number is returned.
 #if defined(_MSC_VER) && _MSC_VER < 1900
 
-	inline
+    AI_FORCE_INLINE
     int c99_ai_vsnprintf(char *outBuf, size_t size, const char *format, va_list ap) {
 		int count(-1);
 		if (0 != size) {
@@ -68,7 +70,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 		return count;
 	}
 
-	inline
+    AI_FORCE_INLINE
     int ai_snprintf(char *outBuf, size_t size, const char *format, ...) {
 		int count;
 		va_list ap;
@@ -89,7 +91,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ///	@param	value   The value to write into the std::string.
 ///	@return	The value as a std::string
 template <typename T>
-inline
+AI_FORCE_INLINE
 std::string to_string( T value ) {
     std::ostringstream os;
     os << value;
@@ -102,7 +104,7 @@ std::string to_string( T value ) {
 ///	@param	begin   The first character of the string.
 /// @param  end     The last character
 ///	@return	The float value, 0.0f in cas of an error.
-inline
+AI_FORCE_INLINE
 float ai_strtof( const char *begin, const char *end ) {
     if ( nullptr == begin ) {
         return 0.0f;
@@ -124,7 +126,7 @@ float ai_strtof( const char *begin, const char *end ) {
 ///	@param	toConvert   Value to convert
 ///	@return	The hexadecimal string, is empty in case of an error.
 template<class T>
-inline
+AI_FORCE_INLINE
 std::string DecimalToHexa( T toConvert ) {
     std::string result;
     std::stringstream ss;