2015-10-10 132 views
0

从我能收集的信息来看,这应该起作用,不是吗?初始化基类

struct ViewOfFile { 
    void* p = nullptr; 

    ViewOfFile(HANDLE hMap, int64_t OffsetB, SIZE_T SizeB, bool WriteAccess) { 
     DWORD ViewAccessMode = FILE_MAP_READ | (WriteAccess ? FILE_MAP_WRITE : NULL); 
     LARGE_INTEGER LI = { OffsetB }; 
     p = MapViewOfFile(hMap, ViewAccessMode, LI.HighPart, LI.LowPart, SizeB); 
     if (p == nullptr) throw Exception("ViewOfFile: Failed to create view."); 
    } 
    ~ViewOfFile() { 
     if (p) UnmapViewOfFile(p); 
    } 
    operator void*() const { return p; } 
    operator char*() const { return reinterpret_cast<char*>(p); } 
}; 

template <typename T> 
struct ViewOfFileAs : ViewOfFile { 
    T* as; 
    ViewOfFile(HANDLE hMap, int64_t OffsetB, SIZE_T SizeB, bool WriteAccess) : ViewOfFile(hMap, OffsetB, SizeB, WriteAccess) { 
     as = reinterpret_cast<T*>(p); 
    } 
}; 

但是,模板类的构造函数给我一个错误“只有构造函数可以有基/成员初始化列表”。这是为什么发生?

+0

无关,但你为什么用'NULL'宏来写一个整数值? –

+0

您可能想要将模板构造函数从ViewOfFile重命名为ViewOfFileAs –

+0

@NeilKirk,因为它应该是0并且像其他宏一样是紫色的,它的时尚选择 – user81993

回答

2

我想你只是在模板结构的定义中有一个错字:你写了ViewOfFile而不是ViewOfFileAs作为构造函数。

+0

doh! :捂脸。 – user81993

0
ViewOfFile(HANDLE hMap, int64_t OffsetB, SIZE_T SizeB, bool WriteAccess) 

应该

ViewOfFileAs(HANDLE hMap, int64_t OffsetB, SIZE_T SizeB, bool WriteAccess)