C++：我需要在这里包含这个头，我不知道为什么

这是一个GameBoy的模拟器我一直在工作，我需要包括在这一点上这个头：https://github.com/ryanterry131/JaxBoy/blob/master/src/core/memory/MemoryBus.h#L17 C++：我需要在这里包含这个头，我不知道为什么

要不然我得到了相当大的错误，我不明白：

In file included from src/core/GameBoy.cpp:15: 
In file included from src/core/GameBoy.h:19: 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:2535:27: error: 
    invalid application of 'sizeof' to an incomplete type 
    'Memory::MemoryController' 
     static_assert(sizeof(_Tp) > 0, "default_delete can not delet... 
         ^~~~~~~~~~~ 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:2736:13: note: 
    in instantiation of member function 
    'std::__1::default_delete<Memory::MemoryController>::operator()' requested 
    here 
     __ptr_.second()(__tmp); 
     ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:2704:46: note: 
    in instantiation of member function 
    'std::__1::unique_ptr<Memory::MemoryController, 
    std::__1::default_delete<Memory::MemoryController> >::reset' requested 
    here 
_LIBCPP_INLINE_VISIBILITY ~unique_ptr() {reset();} 
             ^
src/core/memory/MemoryBus.h:31:7: note: in instantiation of member function 
    'std::__1::unique_ptr<Memory::MemoryController, 
    std::__1::default_delete<Memory::MemoryController> >::~unique_ptr' 
    requested here 
class MemoryBus 
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:4423:26: note: 
    in instantiation of function template specialization 
    'std::__1::__shared_ptr_emplace<Memory::MemoryBus, 
    std::__1::allocator<Memory::MemoryBus> 
    >::__shared_ptr_emplace<Core::GameBoy *>' requested here 
::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...); 
        ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:4787:29: note: 
    in instantiation of function template specialization 
    'std::__1::shared_ptr<Memory::MemoryBus>::make_shared<Core::GameBoy *>' 
    requested here 
return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...); 
         ^
src/core/GameBoy.cpp:36:23: note: in instantiation of function template 
    specialization 'std::__1::make_shared<Memory::MemoryBus, Core::GameBoy *>' 
    requested here 
memory_bus = std::make_shared<Memory::MemoryBus>(this); 
       ^
src/core/memory/MemoryBus.h:29:7: note: forward declaration of 
    'Memory::MemoryController' 
class MemoryController;

这大概有事情做与的unique_ptr，但我没有该死的线索需要我包括在MemoryBus头说头。

谢谢。

来源

2017-04-12 Ryan Terry

'sizeof'倾斜测量'MemoryController'类的无_full_定义的大小。前向声明对此不足。我不知道错误“sizeof'到一个不完整类型的错误应用”可以更清楚地说明这个... –

创建unique_ptr总是这样吗？ –

在某些情况下，unique_ptr需要类的完整定义。

看看Is std::unique_ptr<T> required to know the full definition of T?

来源

2017-04-12 04:17:41

的“合法”理由错误是unique_ptr需要一个完整的类型。

实际上，你可以避开这个错误：在你的类中声明一个析构函数，它包含unique_ptr（Core::GameBoy？）并在该类的.cpp文件中定义析构函数。

GameBoy.h

class MemoryBus; 

class GameBoy { 
    unique_ptr<MemoryBus> foo; 
public: 
    ~GameBoy(); 
    // ... 
};

GameBoy.cpp

GameBoy::~GameBoy() = default;

来源

2017-04-12 05:19:16 j6t

C++：我需要在这里包含这个头，我不知道为什么

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