Generic Image Library: color_element_type, color_element_reference_type, color_element_const_reference_type, get_color, contains_color

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Classes | Functions
color_element_type, color_element_reference_type, color_element_const_reference_type, get_color, contains_color
ColorBase » Algorithms and Utility Functions

get_color: Named channel accessors More...

## Classes
struct | contains_color< ColorBase, Color >
| A predicate metafunction determining whether a given color base contains a given color. More...
struct | color_element_type< ColorBase, Color >
| Specifies the type of the element associated with a given color tag. More...
struct | color_element_reference_type< ColorBase, Color >
| Specifies the return type of the mutable element accessor by color name, get_color(color_base, Color());. More...
struct | color_element_const_reference_type< ColorBase, Color >
| Specifies the return type of the constant element accessor by color name, get_color(color_base, Color());. More...

## Functions
template<typename ColorBase , typename Color >
auto | get_color (ColorBase &cb, Color=Color()) -> typename color_element_reference_type< ColorBase, Color >::type
| Mutable accessor to the element associated with a given color name.
template<typename ColorBase , typename Color >
auto | get_color (const ColorBase &cb, Color=Color()) -> typename color_element_const_reference_type< ColorBase, Color >::type
| Constant accessor to the element associated with a given color name.

## Detailed Description

get_color: Named channel accessors

Support for accessing the elements of a color base by color name

Example: A function that takes a generic pixel containing a red channel and sets it to 100%:

template <typename Pixel>
void set_red_to_max(Pixel& pixel) {
boost::function_requires<MutablePixelConcept<Pixel> >();
static_assert(contains_color<Pixel, red_t>::value, "");
using red_channel_t = typename color_element_type<Pixel, red_t>::type;
get_color(pixel, red_t()) = channel_traits<red_channel_t>::max_value();
}
boost::gil::get_color
auto get_color(ColorBase &cb, Color=Color()) -> typename color_element_reference_type< ColorBase, Color >::type
Mutable accessor to the element associated with a given color name.
Definition color_base_algorithm.hpp:190