Method map

ext/include/llvm/Support/JSON.h:664–669

  /// Maps a property to a field, if it exists.
  template <typename T> bool map(StringRef Prop, T &Out) {
    assert(*this && "Must check this is an object before calling map()");
    if (const Value *E = O->get(Prop))
      return fromJSON(*E, Out);
    return false;
  }

  /// Maps a property to a field, if it exists.
  /// (Optional requires special handling, because missing keys are OK).