考虑以下代码:
template<unsigned int... TSIZE>
struct Base {};
template<unsigned int TORDER, unsigned int TDIM>
struct Derived : public Base</* TDIM, TDIM, ... TDIM (TORDER times) */> {};
您认为在这个例子的第二行正确生成 Base 的模板参数是否存在技巧？例如我想要 Derived<3, 5>从 Base<5, 5, 5> 继承.怎么做？
最佳答案
有了一点 TMP，这毕竟不是那么难:
template<unsigned ToGo, class T, T Arg, template<T...> class Target, T... Args>
struct generate_pack
: generate_pack<ToGo-1, T, Arg, Target, Args..., Arg>
{ // build up the 'Args' pack by appending 'Arg' ...
};
template<class T, T Arg, template<T...> class Target, T... Args>
struct generate_pack<0, T, Arg, Target, Args...>
{ // until there are no more appends to do
using type = Target<Args...>;
};
template<unsigned Num, class T, T Arg, template<T...> class Target>
using GeneratePack = typename generate_pack<Num, T, Arg, Target>::type;
template<unsigned int... TSIZE>
struct Base{};
template<unsigned int TORDER, unsigned int TDIM>
struct Derived
: GeneratePack<TORDER, unsigned, TDIM, Base>
{
};
关于c++ - 您可以根据大小及其内容生成可变模板包吗？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11966044/