template <typename T, typename CharT = char, typename Enable = void>
scanner struct
Scanner type, can be customized to enable scanning of user-defined types
Constructors, destructors, conversion operators
- scanner() deleted
- Default fallback implementation, not constructible, always an error.
Public functions
Function documentation
template <typename T, typename CharT, typename Enable>
template <typename ParseContext>
auto scn::v3::scanner::parse(ParseContext& pctx) → expected< typename ParseContext::iterator, scan_error > deleted constexpr
template <typename ParseContext>
| Returns | On success, an iterator pointing to the } character at the end of the replacement field in the format string. Will cause an error, if the returned iterator doesn't point to a } character. |
|---|
Parse the format string contained in pctx, and populate *this with the parsed format specifier values, to be used later in scan().
Should be constexpr to allow for compile-time format string checking.
A common pattern is to inherit a scanner implementation from another scanner, while only overriding scan(), and keeping the same parse(), or at least delegating to it.
template <typename T, typename CharT, typename Enable>
template <typename Context>
auto scn::v3::scanner::scan(T& value,
Context& ctx) const → expected< typename Context::iterator, scan_error > deleted
template <typename Context>
| Returns | On success, an iterator pointing past the last character consumed from ctx. |
|---|
Scan a value of type T from ctx into value, using the format specs in *this, populated by parse().
value is guaranteed to only be default initialized.