在初始化vector
unique_ptr
时,有一些问题可以使语法正确。
class Thing
{};
class Spider: public Thing
{};
最初尝试过:
std::vector<std::unique_ptr<Thing>> stuff{std::unique_ptr<Thing>(new Spider)};
但这需要复制构造函数(unique_ptr
没有)。
game.cpp:62:46: note: in instantiation of member function 'std::__1::vector<std::__1::unique_ptr<Thing, std::__1::default_delete<Thing> >, std::__1::allocator<std::__1::unique_ptr<Thing, std::__1::default_delete<Thing> > > >::vector' requested here
std::vector<std::unique_ptr<Thing>> WestOfStartThings{std::unique_ptr<Thing>(new Spider)};
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:2510:31: note: copy constructor is implicitly deleted because 'unique_ptr<Thing, std::__1::default_delete<Thing> >' has a user-declared move constructor
_LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
所以我试着让move构造函数激活:
std::vector<std::unique_ptr<Thing>> WestOfStartThings{std::move(std::unique_ptr<Thing>(new Spider))};
但仍然没有运气。
game.cpp:62:46: note: in instantiation of member function 'std::__1::vector<std::__1::unique_ptr<Thing, std::__1::default_delete<Thing> >, std::__1::allocator<std::__1::unique_ptr<Thing, std::__1::default_delete<Thing> > > >::vector' requested here
std::vector<std::unique_ptr<Thing>> WestOfStartThings{std::move(std::unique_ptr<Thing>(new Spider))};
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:2510:31: note: copy constructor is implicitly deleted because 'unique_ptr<Thing, std::__1::default_delete<Thing> >' has a user-declared move constructor
_LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
答案 0 :(得分:0)
您是否特别关注使用初始化程序列表?
如果您的目标只是创建上面的向量,则可以使用以下语法:
std::vector<std::unique_ptr<Thing>> WestOfStartThings;
WestOfStartThing.emplace_back(new Spider);
如果您确实想要专门使用初始化列表,我相信语法是:
std::vector<std::unique_ptr<Thing>> stuff{std::unique_ptr<Thing>{new Spider}};
使用初始化器而不是构造函数创建unique_ptr。