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43 lines
1.5 KiB
C++
43 lines
1.5 KiB
C++
#pragma once
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#include <type_traits>
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#include <boost/range/counting_range.hpp>
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#include <boost/range/adaptor/transformed.hpp>
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namespace ext
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{
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/// For loop adaptor which is used to iterate through a half-closed interval [begin, end).
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template <typename BeginType, typename EndType>
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inline auto range(BeginType begin, EndType end)
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{
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using CommonType = typename std::common_type<BeginType, EndType>::type;
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return boost::counting_range<CommonType>(begin, end);
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}
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template <typename Type>
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inline auto range(Type end)
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{
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return range<Type, Type>(static_cast<Type>(0), end);
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}
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/// The same as range(), but every value is casted statically to a specified `ValueType`.
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/// This is useful to iterate through all constants of a enum.
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template <typename ValueType, typename BeginType, typename EndType>
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inline auto range_with_static_cast(BeginType begin, EndType end)
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{
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using CommonType = typename std::common_type<BeginType, EndType>::type;
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if constexpr (std::is_same_v<ValueType, CommonType>)
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return boost::counting_range<CommonType>(begin, end);
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else
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return boost::counting_range<CommonType>(begin, end)
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| boost::adaptors::transformed([](CommonType x) -> ValueType { return static_cast<ValueType>(x); });
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}
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template <typename ValueType, typename EndType>
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inline auto range_with_static_cast(EndType end)
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{
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return range_with_static_cast<ValueType, EndType, EndType>(static_cast<EndType>(0), end);
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}
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}
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