The postfix tax

Two loops. Same answer. One makes 1000 extra copies.

Keep the same output. Remove the extra iterator copies.

why it matters

it++ returns the old iterator — so it makes a copy first. Here the iterator is heavy.

functional tests · copy counter · quality grade

02editorread-only demo

1// #207 — join every element into one string

2template <class It>

3std::string join(It it, It end) {

4 std::string s;

5 for (; it != end; it++) {

6 s += *it;

7 }

8 return s;

03runneridle

$ run — runs solution.cpp and counts iterator copies

// nothing has run yet. on $ run:

› build & run your code ~400ms

› check output against the reference

› count iterator copies while it runs

› grade the C++, not just the answer

press $ run or ⌘↵ to start

A normal checker sees the answer. CppForge sees the cost.

build —output —copies —· guest mode: progress is not savedclang 14 · c++17 · copy counter