SeqAn3  3.2.0-rc.1
The Modern C++ library for sequence analysis.
seqan3::pack_traits Namespace Reference

Namespace containing traits for working on type packs. More...

Functions

Type pack traits (return a single type)
template<ptrdiff_t idx, typename... pack_t>
 requires (idx >=0 &&idx< sizeof...(pack_t))||(-idx<
 Return the type at given index from the type pack. More...
 
template<typename... pack_t>
 requires (sizeof...(pack_t) > 0) using front = typename decltype((std::type_identity<pack_t>{}, ...))::type
 Return the first type from the type pack. More...
 

Variables

Type pack traits (return a value)
template<typename... pack_t>
constexpr size_t size = sizeof...(pack_t)
 The size of a type pack. More...
 
template<typename query_t , typename... pack_t>
constexpr ptrdiff_t count = (std::is_same_v<query_t, pack_t> + ... + 0)
 Count the occurrences of a type in a pack. More...
 
template<typename query_t , typename... pack_t>
constexpr ptrdiff_t find = seqan3::pack_traits::detail::find<query_t, pack_t...>()
 Get the index of the first occurrence of a type in a pack. More...
 
template<template< typename > typename pred_t, typename... pack_t>
constexpr ptrdiff_t find_if = seqan3::pack_traits::detail::find_if<pred_t, pack_t...>()
 Get the index of the first type in a pack that satisfies the given predicate. More...
 
template<typename query_t , typename... pack_t>
constexpr bool contains = (find<query_t, pack_t...> != -1)
 Whether a type occurs in a pack or not. More...
 

Type pack traits (return a type list)

template<template< typename > typename trait_t, typename... pack_t>
using transform = seqan3::type_list< trait_t< pack_t >... >
 Apply a transformation trait to every type in the pack and return a seqan3::type_list of the results. More...
 
template<ptrdiff_t i, typename... pack_t>
 requires (i >=0 &&i<=size< pack_t... >) using take = typename decltype(detail::split_after<i, pack_t...>(type_list<>{}))::second_type
 Return a seqan3::type_list of the first n types in the type pack. More...
 
template<typename replace_t , std::ptrdiff_t i, typename... pack_t>
 requires (i >=0 &&i< size< pack_t... >) using replace_at
 Replace the type at the given index with the given type. More...
 

Detailed Description

Namespace containing traits for working on type packs.