Boost GIL


nth_channel_deref_fn< SrcP > Struct Template Reference

Function object that returns a grayscale reference of the N-th channel of a given reference. Models: PixelDereferenceAdaptorConcept. More...

#include <image_view_factory.hpp>

Public Types

using const_t = nth_channel_deref_fn<const_ref_t>
using value_type = typename pixel_value_type<channel_t,gray_layout_t>::type
using const_reference = typename pixel_reference_type<channel_t,gray_layout_t,false,false>::type
using argument_type = SrcP
using reference = mp11::mp_if_c<is_mutable, ref_t, value_type>
using result_type = reference

Public Member Functions

 nth_channel_deref_fn (int n=0)
template<typename P>
 nth_channel_deref_fn (const nth_channel_deref_fn< P > &d)
auto operator() (argument_type srcP) const -> result_type

Public Attributes

int _n

Static Public Attributes

static constexpr bool is_mutable

Detailed Description

template<typename SrcP>
struct boost::gil::detail::nth_channel_deref_fn< SrcP >

Function object that returns a grayscale reference of the N-th channel of a given reference. Models: PixelDereferenceAdaptorConcept.

If the input is a pixel value or constant reference, the function object is immutable. Otherwise it is mutable (and returns non-const reference to the n-th channel)

Member Data Documentation

◆ is_mutable

template<typename SrcP>
bool is_mutable
staticconstexpr
Initial value:
=
Given a model of a pixel, determines whether the model represents a pixel reference (as opposed to pi...
Definition metafunctions.hpp:218
Determines if the given pixel reference is mutable (i.e. its channels can be changed)
Definition metafunctions.hpp:231

The documentation for this struct was generated from the following file: