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考慮這種可變參數模板瘋狂從一種類型轉換的陣列到另一:Variadic模板元編程:鏗鏘++或g ++中的錯誤?
#include <array>
#include <type_traits>
template <typename Type>
class Converter
{
public:
template <typename OtherType, unsigned int OtherSize, class Array, typename... Types, class = typename std::enable_if<sizeof...(Types) != OtherSize>::type>
static constexpr const std::array<OtherType, OtherSize> convert(const Array source, const Types&... values);
template <typename OtherType, unsigned int OtherSize, class Array, typename... Types, class = typename std::enable_if<sizeof...(Types) == OtherSize>::type>
static constexpr const std::array<OtherType, OtherSize> convert(const Array, const Types... values);
};
template <typename Type>
template <typename OtherType, unsigned int OtherSize, class Array, typename... Types, class>
constexpr const std::array<OtherType, OtherSize> Converter<Type>::convert(const Array source, const Types&... values)
{
return convert<OtherType, OtherSize>(source, values..., OtherType(source[sizeof...(values)]));
}
template <typename Type>
template <typename OtherType, unsigned int OtherSize, class Array, typename... Types, class>
constexpr const std::array<OtherType, OtherSize> Converter<Type>::convert(const Array, const Types... values)
{
return std::array<OtherType, OtherSize>({{values...}});
}
int main(int argc, char* argv[])
{
Converter<double>::convert<int, 3>(std::array<double, 3>({{1., 2., 3.}}));
return 0;
}
此代碼編譯以及下克++ 4.7和g ++ 4.8但不低於鐺++ 3.2:
main.cpp:16:67: error: conflicting types for 'convert'
constexpr const std::array<OtherType, OtherSize> Converter<Type>::convert(const Array source, const Types&... values)
^
main.cpp:9:65: note: previous declaration is here
static constexpr const std::array<OtherType, OtherSize> convert(const Array source, const Types&... values);
^
main.cpp:23:67: error: conflicting types for 'convert'
constexpr const std::array<OtherType, OtherSize> Converter<Type>::convert(const Array, const Types... values)
^
main.cpp:11:65: note: previous declaration is here
static constexpr const std::array<OtherType, OtherSize> convert(const Array, const Types... values);
g ++是否過於寬容,或者它是鏗鏘++的錯誤(如果是這樣,是否有一個公共bugng的bug追蹤器)?
並且與其他一些主要編譯器供應商不同,此類錯誤修復很快就會在新版本中發佈。 – TemplateRex 2013-05-09 21:53:13