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//============================================================================
// Author : Svenson Han Göthel and Sven Göthel
// Version : 0.1
// Copyright : MIT
// Description : C++ Lesson 4.0 Simple binary search and sorted insert algorithm using C++
//============================================================================
#include <cstdio>
#include <iostream>
#include <cmath>
#include <vector>
#include <limits>
#include <cassert>
/**
* Lesson 3.9 STL iterator and difference_type limitations (signed integer)
*/
int main(int, const char**) {
// regular pointer arithmetic adding usigned integer size_t,
// i.e. using maximum value range
{
int array[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
int* plala = &array[0];
for(size_t i=0; i<9l; ++i) {
array[i] = *(plala + i) + 1;
}
}
// Because std::vector<>::begin() iterator performs arithmetic
// using a signed difference_type, we need to use such a signed type
// here to avoid `bugprone-narrowing-conversions` (LINT)
//
// Now, isn't this odd as std::vector<>::size() uses unsigned size_type,
// aka size_t and mentioned iterator hence lose half the value range possible?
{
// index operator[] can use unsigned size_t, full range
std::vector<int> array(10, 0);
for(size_t i=0; i<array.size(); ++i) {
// using unsigned int as index is legal, also full range
array[i] += 1;
}
// now iterating via iterator, loss of full range
typedef std::vector<int>::difference_type iterdiff_t;
iterdiff_t sz = array.cend() - array.cbegin() - 1;
for(iterdiff_t i=0; i<sz; ++i) {
// begin() iterator is signed hence adding signed difference_type, loss of full range
// same is true w/ all other operations like insert where an iterator is being used
*(array.begin() + i) += 1;
}
// or .. same issues
typedef std::vector<int>::iterator iter_t;
for(iter_t i=array.begin(); i < array.end(); ++i) {
*i += 1;
}
}
return 0;
}
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