diff options
Diffstat (limited to 'src/sexpr/variant.tcc')
| -rw-r--r-- | src/sexpr/variant.tcc | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/sexpr/variant.tcc b/src/sexpr/variant.tcc index 424a8f1..ce820bf 100644 --- a/src/sexpr/variant.tcc +++ b/src/sexpr/variant.tcc @@ -24,6 +24,16 @@ namespace tmwa { namespace sexpr { + template<size_t v> + constexpr + size_t not_negative_one() + { + return v; + } + template<> + constexpr + size_t not_negative_one<-1>() = delete; + class VariantFriend { public: @@ -77,7 +87,7 @@ namespace sexpr template<class W, class V> constexpr static size_t get_state_for() { - return std::remove_reference<V>::type::DataType::template index<W>(); + return not_negative_one<std::remove_reference<V>::type::DataType::template index<W>()>(); } }; @@ -104,7 +114,7 @@ namespace sexpr try { data.template construct<C, A...>(std::forward<A>(a)...); - state = Union<D, T...>::template index<C>(); + state = not_negative_one<Union<D, T...>::template index<C>()>(); } catch(...) { @@ -244,7 +254,7 @@ namespace sexpr template<class E> E *Variant<D, T...>::get_if() { - if (state == Union<D, T...>::template index<E>()) + if (state == not_negative_one<Union<D, T...>::template index<E>()>()) return data.template get<E>(); return nullptr; } @@ -253,7 +263,7 @@ namespace sexpr template<class E> const E *Variant<D, T...>::get_if() const { - if (state == Union<D, T...>::template index<E>()) + if (state == not_negative_one<Union<D, T...>::template index<E>()>()) return data.template get<E>(); return nullptr; } |