@brief create an empty HashedStringRef

The implicit cast is necessary when Result has more than one single-argument constructor (e.g. Result is std::vector<int>) and R has a type conversion

Returns the floating-point number that represent positive infinity.

Initializes an RE from its string representation.

Initializes this object with a copy of the input.

Initializes this object with a reference of the input.

Tests that ResultOf() can explain the match result.

An int can be statically (although not implicitly) cast to a IntValue.

The c'tor makes a copy of function_impl (either a function pointer or a functor).

The c'tor takes ownership of the callback.

The c'tor takes ownership of the callback.

The c'tor makes a copy of function_impl (either a function pointer or a functor).

Returns bool if this node is a declaration.

Returns bool if this node is a definition.

Returns bool if this node exportable from a header file.