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Determine if a Type is a Character
is_char

is_char is a metafunction that detects if a given type is a character.

Module Headers
#include <boost/spirit/home/support/string_traits.hpp>

Also, see Include Structure.

[Note] Note

This header file does not need to be included directly by any user program as it is normally included by other Spirit header files relying on its content.

Namespace

Name

boost::spirit::traits

Synopsis
template <typename T>
struct is_char
{
    <unspecified>;
};
Template parameters

Parameter

Description

Default

T

The type to detect.

none

Notation

T

An arbitrary type

Expression Semantics

Expression

Semantics

is_char<T>::type

mpl::true_ if T should be treated as a character type, and mpl::false_ otherwise. Generally, any implementation of is_char needs to behave as if if was a MPL Boolean Constant.

Predefined Specializations

Type

Semantics

T

mpl::false_

T const

is_char<T>

char

mpl::true_

wchar_t

mpl::true_

When to implement

This customization point needs to be implemented for any strings that use a type other than char or `wchar_t to store character data.

Related Attribute Customization Points

If this customization point is implemented, the following other customization points need to be implemented as well.

Name

When to implement

traits::is_string

Whenever is_char is implemented.

traits::char_type_of

Whenever is_char is implemented.


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