Const vector of non-const objects

c++ vector constants const-correctness
Humble Debugger picture Humble Debugger · Jul 25, 2011 · Viewed 13.4k times · Source

In defining a function in an interface :

virtual void ModifyPreComputedCoeffs ( std::vector < IndexCoeffPair_t > & model_ ) = 0;

we want to specify that the vector model_ should not be altered in the sense push_back etc operations should not be done on the vector, but the IndexCoeffPair_t struct objects in the model_ could be changed. How should we specify that ?

virtual void ModifyPreComputedCoeffs ( const std::vector < IndexCoeffPair_t > & model_ ) = 0;

does not work I think.

Answer

Mark Ransom picture Mark Ransom · Jul 25, 2011

Rather than passing the vector into the function, do what the standard library does and pass a pair of iterators instead.

virtual void ModifyPreComputedCoeffs ( std::vector < IndexCoeffPair_t >::iterator & model_begin, std::vector < IndexCoeffPair_t >::iterator & model_end )

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