There exist several ways to give a std::vector as an array. Suppose we have a vector std::vector vec. The ways are
- &vec[0]
- &vec.front()
- vec.data() supported by C++11
The following code should output as
print integer array: 0,1,2,3,4, print integer vector: 0,1,2,3,4, print float array: 0,1,4,9,16, print float vector: 0,1,4,9,16, print double array: 0,1,8,27,64, print double vector: 0,1,8,27,64,
[code lang="cpp"]
include <iostream>
include <vector>
template <typename ValueType> void printArray( const ValueType* array, const int size ) { for(int n = 0; n < size; ++n) { std::cout << array[n] << ","; } std::cout << std::endl; }
template <typename ValueType> void printVector( const std::vector<ValueType> vec ) { for(int n = 0; n < vec.size(); ++n) { std::cout << vec[n] << ","; } std::cout << std::endl; }
template <typename ValueType> ValueType square( const ValueType x ) { return x*x; }
template <typename ValueType> ValueType cube( const ValueType x ) { return xxx; }
int main() { int numData = 5; std::vector<int> vecI(numData); std::vector<float> vecF(numData); std::vector<double> vecD(numData);
for(int n = 0; n < numData; ++n)
{
vecI[n] = n;
vecF[n] = square((float)n);
vecD[n] = cube((double)n);
}
std::cout << "print integer array: ";
printArray(&vecI.front(), vecI.size());
std::cout << "print integer vector: ";
printVector(vecI);
std::cout << "print float array: ";
printArray(&vecF[0], vecF.size());
std::cout << "print float vector: ";
printVector(vecF);
std::cout << "print double array: ";
printArray(vecD.data(), vecD.size());
std::cout << "print double vector: ";
printVector(vecD);
} [/code]
