//: C07:IndexingVsAt.cpp
// Comparing "at()" to operator[].
#include <ctime>
#include <deque>
#include <iostream>
#include <vector>
#include "../require.h"
using namespace std;
int main(int argc, char* argv[]) {
long count = 1000;
int sz = 1000;
if(argc >= 2) count = atoi(argv[1]);
if(argc >= 3) sz = atoi(argv[2]);
vector<int> vi(sz);
clock_t ticks = clock();
for(int i1 = 0; i1 < count; i1++)
for(int j = 0; j < sz; j++)
vi[j];
cout << "vector[] "
<< clock() - ticks << endl;
ticks = clock();
for(int i2 = 0; i2 < count; i2++)
for(int j = 0; j < sz; j++)
vi.at(j);
cout << "vector::at() " <<
clock()-ticks <<endl;
deque<int> di(sz);
ticks = clock();
for(int i3 = 0; i3 < count; i3++)
for(int j = 0; j < sz; j++)
di[j];
cout << "deque[] " << clock() -
ticks << endl;
ticks = clock();
for(int i4 = 0; i4 < count; i4++)
for(int j = 0; j < sz; j++)
di.at(j);
cout << "deque::at() " <<
clock()-ticks <<endl;
// Demonstrate at() when you go out of bounds:
try {
di.at(vi.size() + 1);
} catch(...) {
cerr << "Exception thrown" <<
endl;
}
} ///:~
As you saw in Chapter 1, different systems may handle the
uncaught exception in different ways, but you ll know one way or another that
something went wrong with the program when using at( ), whereas
it s possible to remain ignorant when using operator[ ].
