From 7d186b016a18fd3421015b274e98b2fc7fdebe76 Mon Sep 17 00:00:00 2001 From: Zachary Turner Date: Sun, 14 May 2017 17:11:05 +0000 Subject: [PATCH] [StringExtras] Add llvm::to_integer. This is a very thin wrapper around StringRef::getAsInteger. It serves three purposes. 1) It allows a cleaner syntax when you have something other than a StringRef - for example, a std::string or an llvm::SmallString. Previously, in this case you would have to write something like: StringRef(MyStr).getAsInteger(0, Result) by explicitly constructing a temporary StringRef. This can be done implicitly however with the new function by just writing: to_integer(MyStr, ...). 2) Correcting the travesty that is getAsInteger's return value. This function returns true on success, and false on failure. While this may cause confusion with people familiar with the getAsInteger API, there seems to be widespread agreement that the return semantics of getAsInteger was a mistake. 3) It allows the Radix to be deduced as a default argument by putting it last in the parameter list. Most uses of getAsInteger pass 0 for the first argument. With this syntax it can just be omitted. llvm-svn: 303011 --- llvm/include/llvm/ADT/StringExtras.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/llvm/include/llvm/ADT/StringExtras.h b/llvm/include/llvm/ADT/StringExtras.h index 26f1192..1c109be 100644 --- a/llvm/include/llvm/ADT/StringExtras.h +++ b/llvm/include/llvm/ADT/StringExtras.h @@ -106,6 +106,13 @@ static inline std::string fromHex(StringRef Input) { return Output; } +/// \brief Convert the string \p S to an integer of the specified type using +/// the radix \p Base. If \p Base is 0, auto-detects the radix. +/// Returns true if the number was successfully converted, false otherwise. +template bool to_integer(StringRef S, N &Num, unsigned Base = 0) { + return !S.getAsInteger(Base, Num); +} + static inline std::string utostr(uint64_t X, bool isNeg = false) { char Buffer[21]; char *BufPtr = std::end(Buffer); -- 2.7.4