考虑以下代码段:
template <typename TF>
void post(TF){ }
template <typename... TFs>
struct funcs : TFs...
{
funcs(TFs... fs) : TFs{fs}... { }
void call()
{
(post([&]{ static_cast<TFs&>(*this)(); }), ...);
}
};
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g ++ 7.0无法编译,出现以下错误:
prog.cc: In lambda function:
prog.cc:10:43: error: parameter packs not expanded with '...':
(post([&]{ static_cast<TFs&>(*this)(); }), ...);
~~~~~~~~~~~~~~~~~~~~~~~~^~
prog.cc:10:43: note: 'TFs'
prog.cc: In member function 'void funcs<TFs>::call()':
prog.cc:10:13: error: operand of fold expression has no unexpanded parameter packs
(post([&]{ static_cast<TFs&>(*this)(); }), …Run Code Online (Sandbox Code Playgroud)