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functional style stdex::optional to std::vector conversion
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#include <experimental/optional> | |
#include <experimental/type_traits> | |
#include <type_traits> | |
#include <utility> | |
#include <vector> | |
namespace stdex = std::experimental; | |
template < | |
typename Optional, | |
typename = std::enable_if_t< | |
stdex::is_same_v< | |
std::decay_t<Optional>, | |
stdex::optional<typename std::decay_t<Optional>::value_type> | |
> | |
> | |
> | |
std::vector<typename std::decay_t<Optional>::value_type> toVector(Optional&& optional) | |
{ | |
typedef typename std::decay_t<Optional>::value_type value_type; | |
typedef std::conditional_t< | |
stdex::is_lvalue_reference_v<Optional>, | |
std::add_lvalue_reference_t<value_type>, | |
value_type | |
> value_type_forward; | |
auto result = std::vector<value_type>{}; | |
if (optional) | |
result.push_back(std::forward<value_type_forward>(*optional)); | |
return result; | |
} |
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