Removed stringstream from assignment from double.

MString.cpp

@@ -84,11 +84,9 @@ namespace coreutils {
    }
 
    MString::MString(double value) {
-      std::stringstream temp;
-      temp << std::format("{}", value);
-      std::string temp2 = temp.str();
-      setSize(temp2.length());
-      memcpy(this->data, (char *)temp2.data(), temp2.length());
+      std::string temp = std::format("{}", value);
+      setSize(temp.length());
+      memcpy(this->data, (char *)temp.data(), temp.length());
       cursor = this->data;
    }
    
@@ -133,11 +131,9 @@ namespace coreutils {
    }
 
    MString &MString::operator=(double value) {
-      std::stringstream temp;
-      temp << std::format("{}", value);
-      std::string temp2 = temp.str();
-      setSize(temp2.length());
-      memcpy(this->data, (char *)temp2.data(), temp2.length());
+      std::string temp = std::format("{}", value);
+      setSize(temp.length());
+      memcpy(this->data, (char *)temp.data(), temp.length());
       cursor = this->data;
       return *this;
    }