algorithm.md

Algorithms

Header: <esu/algorithm.hpp>
Namespace: esu

---

for_each_pair

Applies the function object to adjacent pairs of elements in the range

template<class Forward_iterator1, class Forward_iterator2, class Fn>
Fw_it for_each_pair(Forward_iterator1 first, Forward_iterator2 last, Fn fn);

Applies the given function object fn to adjacent pairs of elements in the range [first, last), in order.

Parameters:

• first, last - the range to apply the function object to,
• fn - the function object to be applied, the signature should be equivalent to the following: void func(T& a, T& b);; the type T must be such that an object of type Fw_it can be dereferenced and then implicitly converted to T.

Return value: the iterator pointing to the last element in the range; first if the range contains less than two elements.

Example:

std::vector v{1, 2, 3, 4};
for_each_pair(v.begin(), v.end(),
    [](int a, int b) { std::cout << '(' << a << ',' << b << ')'; });
// Outputs: (1,2)(2,3)(3,4)

---

for_each_pair_n

Applies the function object to adjacent pairs of elements in the range

template<class Forward_iterator, typename N, class Fn>
Fw_it for_each_pair_n(Forward_iterator first, N n, Fn fn)

Applies the given function object fn to adjacent pairs of elements in the range [first, first + n), in order.

Parameters:

• first - the beginning of the range to apply the function object to,
• n - the number of pairs to apply the function object to,
• fn - the function object to be applied, the signature should be equivalent to the following: void func(T& a, T& b);; the type T must be such that an object of type Fw_it can be dereferenced and then implicitly converted to T.

Return value: the iterator pointing to the last element in the range; first if the range contains less than two elements (n <= 0).

Example:

std::vector v{1, 2, 3, 4};
for_each_pair_n(v.begin(), 2,
    [](int a, int b) { std::cout << '(' << a << ',' << b << ')'; });
// Output: (1,2)(2,3)