Replace a float cast-attempt with an empty catch block by the excepti…

…on-less C-style std::strtof call. It's used a lot during map load.

libs/string/convert.h

@@ -3,6 +3,7 @@
 #include "math/Vector3.h"
 #include "math/Vector4.h"
 #include <sstream>
+#include <cstdlib>
 
 namespace string
 {
@@ -242,6 +243,20 @@ template<typename Src> float to_float(const Src& src)
 }
 #endif
 
+// Attempts to convert the given source string to a float value,
+// returning true on success. The value reference will then be holding
+// the resulting float value (or 0 in case of failure).
+// Note: this is using the exception-less std::strtof, making it preferable
+// over the string::convert<float> method (in certain hot code paths).
+inline bool tryConvertToFloat(const std::string& src, float& value)
+{
+    char* lastChar;
+    auto* firstChar = src.c_str();
+    value = std::strtof(firstChar, &lastChar);
+
+    return lastChar != firstChar;
+}
+
 // Convert the given type to a std::string
 template<typename Src> 
 inline std::string to_string(const Src& value)

radiantcore/shaders/ShaderExpression.cpp

@@ -338,16 +338,13 @@ class ShaderExpressionParser
 			else
 			{
 				// Attempt to convert the token into a floating point value
-				try
-				{
-					float value = std::stof(token);
-
-					_tokeniser.nextToken(); // valid token, exhaust
+                float value;
+                if (string::tryConvertToFloat(token, value))
+                {
+                    _tokeniser.nextToken(); // valid token, exhaust
 
-					return std::make_shared<ConstantExpression>(value);
-				}
-				catch (std::invalid_argument&)
-				{}
+                    return std::make_shared<ConstantExpression>(value);
+                }
 			}
 		}