/// A wrapper around a string literal that serves as a proxy for constructing
/// global tables of StringRefs with the length computed at compile time.
- /// Using this class with a non-literal char array is considered undefined
- /// behavior. To prevent this, it is recommended that StringLiteral *only*
- /// be used in a constexpr context, as such:
+ /// In order to avoid the invocation of a global constructor, StringLiteral
+ /// should *only* be used in a constexpr context, as such:
///
/// constexpr StringLiteral S("test");
///
- /// Note: There is a subtle behavioral difference in the constructor of
- /// StringRef and StringLiteral, as illustrated below:
- ///
- /// constexpr StringLiteral S("a\0b"); // S.size() == 3
- /// StringRef S("a\0b"); // S.size() == 1
- ///
class StringLiteral : public StringRef {
public:
template <size_t N>
- constexpr StringLiteral(const char (&Str)[N]) : StringRef(Str, N - 1) {}
+ constexpr StringLiteral(const char (&Str)[N])
+#if __has_attribute(enable_if)
+ __attribute((enable_if(__builtin_strlen(Str) == N - 1,
+ "invalid string literal")))
+#endif
+ : StringRef(Str, N - 1) {
+ }
};
/// @name StringRef Comparison Operators
}
LLVM_ATTRIBUTE_ALWAYS_INLINE
- inline bool operator!=(StringRef LHS, StringRef RHS) {
- return !(LHS == RHS);
- }
+ inline bool operator!=(StringRef LHS, StringRef RHS) { return !(LHS == RHS); }
inline bool operator<(StringRef LHS, StringRef RHS) {
return LHS.compare(RHS) == -1;