str.erase(std::remove(str.begin(), str.end(), 'a'), str.end());

template <class ForwardIterator, class T> ForwardIterator remove (ForwardIterator first, ForwardIterator last, const T& val);

// remove_if example
#include <iostream> // std::cout #include <algorithm> // std::remove_if bool IsOdd (int i) { return ((i%2)==1); } int main () { int myints[] = {1,2,3,4,5,6,7,8,9}; // 1 2 3 4 5 6 7 8 9 // bounds of range: int* pbegin = myints; // ^ int* pend = myints+sizeof(myints)/sizeof(int); // ^ ^ pend = std::remove_if (pbegin, pend, IsOdd); // 2 4 6 8 ? ? ? ? ? // ^ ^ std::cout << "the range contains:"; for (int* p=pbegin; p!=pend; ++p) std::cout << ' ' << *p; std::cout << '\n'; return 0; }

myvector contains: 10 30 30 10 10 0 0 0

template <class InputIterator, class OutputIterator, class T> OutputIterator remove_copy (InputIterator first, InputIterator last, OutputIterator result, const T& val);

// remove_copy example
#include <iostream> // std::cout #include <algorithm> // std::remove_copy #include <vector> // std::vector int main () { int myints[] = {10,20,30,30,20,10,10,20}; // 10 20 30 30 20 10 10 20 std::vector<int> myvector (8); std::remove_copy (myints,myints+8,myvector.begin(),20); // 10 30 30 10 10 0 0 0 std::cout << "myvector contains:"; for (std::vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it) std::cout << ' ' << *it; std::cout << '\n'; return 0; }

myvector contains: 10 30 30 10 10 0 0 0