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#ifndef VARIANT_INL_H_
#error "Direct inclusion of this file is not allowed, include variant.h"
// For the sake of sane code completion.
#include "variant.h"
#endif
#include <type_traits>
namespace NYT {
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class T>
struct TIndexOf<T>
{
static constexpr size_t Value = std::numeric_limits<size_t>::max();
};
template <class T, class T0, class... Ts>
struct TIndexOf<T, T0, Ts...>
{
static constexpr size_t Value = std::is_same_v<T, T0>
? 0
: 1 + TIndexOf<T, Ts...>::Value;
};
template <size_t Index, class... Ts>
struct TVariantFormatter;
template <size_t Index>
struct TVariantFormatter<Index>
{
template <class TVariant>
static void Do(TStringBuilderBase* /*builder*/, const TVariant& /*variant*/, TStringBuf /*spec*/)
{ }
};
template <size_t Index, class T, class... Ts>
struct TVariantFormatter<Index, T, Ts...>
{
template <class TVariant>
static void Do(TStringBuilderBase* builder, const TVariant& variant, TStringBuf spec)
{
if (variant.index() == Index) {
FormatValue(builder, std::get<Index>(variant), spec);
} else {
TVariantFormatter<Index + 1, Ts...>::Do(builder, variant, spec);
}
}
};
} // namespace NDetail
template <class... Ts>
void FormatValue(TStringBuilderBase* builder, const std::variant<Ts...>& variant, TStringBuf spec)
{
NDetail::TVariantFormatter<0, Ts...>::Do(builder, variant, spec);
}
template <class... Ts>
TString ToString(const std::variant<Ts...>& variant)
{
return ToStringViaBuilder(variant);
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT
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