diff options
| -rw-r--r-- | llvm/include/llvm/ADT/StringSwitch.h | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/llvm/include/llvm/ADT/StringSwitch.h b/llvm/include/llvm/ADT/StringSwitch.h index 7ac0f60f287..7dd5647df60 100644 --- a/llvm/include/llvm/ADT/StringSwitch.h +++ b/llvm/include/llvm/ADT/StringSwitch.h @@ -38,28 +38,24 @@ namespace llvm { /// .Cases("violet", "purple", Violet) /// .Default(UnknownColor); /// \endcode -template<typename T> +template<typename T, typename R = T> class StringSwitch { /// \brief The string we are matching. StringRef Str; - /// \brief The result of this switch statement, once known. - T Result; - - /// \brief Set true when the result of this switch is already known; in this - /// case, Result is valid. - bool ResultKnown; + /// \brief The pointer to the result of this switch statement, once known, + /// null before that. + const T *Result; public: explicit StringSwitch(StringRef Str) - : Str(Str), ResultKnown(false) { } + : Str(Str), Result(0) { } template<unsigned N> StringSwitch& Case(const char (&S)[N], const T& Value) { - if (!ResultKnown && N-1 == Str.size() && + if (!Result && N-1 == Str.size() && (std::memcmp(S, Str.data(), N-1) == 0)) { - Result = Value; - ResultKnown = true; + Result = &Value; } return *this; @@ -92,16 +88,16 @@ public: .Case(S4, Value); } - T Default(const T& Value) { - if (ResultKnown) - return Result; + R Default(const T& Value) const { + if (Result) + return *Result; return Value; } - operator T() { - assert(ResultKnown && "Fell off the end of a string-switch"); - return Result; + operator R() const { + assert(Result && "Fell off the end of a string-switch"); + return *Result; } }; |
