C++: Fix operator regexp + regexp simplification + don't use captures…

… if not needed

components/prism-cpp.js

@@ -1,12 +1,12 @@
 Prism.languages.cpp = Prism.languages.extend('c', {
-	'keyword': /\b(alignas|alignof|asm|auto|bool|break|case|catch|char|char16_t|char32_t|class|compl|const|constexpr|const_cast|continue|decltype|default|delete|do|double|dynamic_cast|else|enum|explicit|export|extern|float|for|friend|goto|if|inline|int|long|mutable|namespace|new|noexcept|nullptr|operator|private|protected|public|register|reinterpret_cast|return|short|signed|sizeof|static|static_assert|static_cast|struct|switch|template|this|thread_local|throw|try|typedef|typeid|typename|union|unsigned|using|virtual|void|volatile|wchar_t|while)\b/,
-	'boolean': /\b(true|false)\b/,
-	'operator': /[-+]{1,2}|!=?|<{1,2}=?|>{1,2}=?|\->|:{1,2}|={1,2}|\^|~|%|&{1,2}|\|?\||\?|\*|\/|\b(and|and_eq|bitand|bitor|not|not_eq|or|or_eq|xor|xor_eq)\b/
+	'keyword': /\b(?:alignas|alignof|asm|auto|bool|break|case|catch|char|char16_t|char32_t|class|compl|const|constexpr|const_cast|continue|decltype|default|delete|do|double|dynamic_cast|else|enum|explicit|export|extern|float|for|friend|goto|if|inline|int|long|mutable|namespace|new|noexcept|nullptr|operator|private|protected|public|register|reinterpret_cast|return|short|signed|sizeof|static|static_assert|static_cast|struct|switch|template|this|thread_local|throw|try|typedef|typeid|typename|union|unsigned|using|virtual|void|volatile|wchar_t|while)\b/,
+	'boolean': /\b(?:true|false)\b/,
+	'operator': /--?|\+\+?|!=?|<{1,2}=?|>{1,2}=?|->|:{1,2}|={1,2}|\^|~|%|&{1,2}|\|\|?|\?|\*|\/|\b(?:and|and_eq|bitand|bitor|not|not_eq|or|or_eq|xor|xor_eq)\b/
 });
 
 Prism.languages.insertBefore('cpp', 'keyword', {
 	'class-name': {
-		pattern: /(class\s+)[a-z0-9_]+/i,
+		pattern: /(class\s+)\w+/i,
 		lookbehind: true
 	}
 });