How to get std vector pointer to the raw data

Question

I m trying to use std  vector as a char array   My function takes in a void pointer   void process data const void  data     Before I simply just used this code   char something      my data here   process data something     Which worked as expected   But now I need the dynamicity of std  vector  so I tried this code instead   vector lt char gt  something   cut  process data something     The question is  how do I pass the char vector to my function so I can access the vector raw data  no matter which format it is     floats  etc     I tried this   process data  amp something     And this   process data  amp something begin       But it returned a pointer to gibberish data  and the latter gave warning  warning C4238  nonstandard extension used   class rvalue used as lvalue

User · Answer

Take a pointer to the first element instead   process data   amp something  0

User · Answer

something data   will return a pointer to the data space of the vector

User · Answer

amp something gives you the address of the std  vector object  not the address of the data it holds    amp something begin   gives you the address of the iterator returned by begin    as the compiler warns  this is not technically allowed because something begin   is an rvalue expression  so its address cannot be taken    Assuming the container has at least one element in it  you need to get the address of the initial element of the container  which you can get via     amp something 0  or  amp something front    the address of the element at index 0   or   amp  something begin    the address of the element pointed to by the iterator returned by begin       In C  11  a new member function was added to std  vector   data     This member function returns the address of the initial element in the container  just like  amp something front     The advantage of this member function is that it is okay to call it even if the container is empty

[c++] How to get std::vector pointer to the raw data?

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