c++ - Is it possible to get a raw pointer to std::vector<unsigned int> data? -


this question has answer here:

i have std::vector filled instructions proprietary hardware. have code construct buffer , manipulate fine.

the problem need make use of library (c based) builds similar proprietary hardware instructions, library expects make raw memory available , return pointer it, library uses write commands.

i accomplish following [pseudo code, nothing real code]:

    void* thelibrarycallback (void* clientdata, unsigned int thelibrarysize)     {         std::vector<unsigned int> cmd = reinterpret_cast<std::vector<unsigned int>>(clientdata);         std::vector<unsigned int>::size_type cmdsize = cmd->size();          (int loop=0;loop<thelibrarysize; loop++)             cmd->push_back(0xdeadbeef);          return cmd->get_raw_pointer_at(sizeof(unsigned int)*cmdsize);   ///<< how can this?     }

the concept add values vector make space, other library modifies them directly.

if cannot ill have consider allocating temporary raw memory, filling out library , copying vector, avoid if possible.

is want possible somehow?

so 2 things:

  1. you can access contiguous memory of vector std::vector::data() or &vec.front().

  2. if in code shown above, you'll returning pointer data disappears when function returns (the vector's destructor run, , data freed).


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