Match a single character from a character set

Synopsis

template<CharSet CS>
constexpr
/* implementation-defined */
delim_rule(CS const& cs) noexcept
requires ! std::is_convertible<
        CS, char>::value;

Description

This matches exactly one character which belongs to the specified character set. The value is a reference to the character in the underlying buffer, expressed as a core::string_view. The function squelch may be used to turn this into void instead. If there is no more input, the error code error::need_more is returned.

Value Type

using value_type = core::string_view;

Example

Rules are used with the function parse.

system::result< core::string_view > rv = parse( "X", delim_rule( alpha_chars ) );

Return Value

A rule which matches a single character from the set.

Parameters

Name	Description
cs	The character set to use.

See Also

alpha_chars, parse, squelch.