#pointer to

Using Pointer to structure to access a pointer element within a structure

I am trying to use a double pointer to a structure to access an element of a structure which is a pointer to an array. However I end up getting Segmentation fault.

typedef struct _cacheLine { uint32_t tag; uint32_t *data; // data points to data stored in // cache line. cache line size is // multiple of 32bits. uint32_t LRUStackBits; // These bits keep track of usage position // of cache line in…

Should my function return a pointer to std::vector, or a reference to std::vector?

I have a std::map<int, std::vector<SomeStruct>>, and provide a query like std::vector<SomeStruct> FindData(int key).

To prevent copying the whole data, I modify it to be std::vector<SomeStruct>& FindData(int key). But, there will be no data for certain key, so sometimes I have nothing to return. In that case, I declare a file scope variable that is an empty std::vector<SomeStruct>and return it.