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Diffstat (limited to 'c++.html.markdown')
| -rw-r--r-- | c++.html.markdown | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/c++.html.markdown b/c++.html.markdown index e45c73c3..74bd8913 100644 --- a/c++.html.markdown +++ b/c++.html.markdown @@ -765,6 +765,22 @@ Foo f1 = fooSub; Foo f1; f1 = f2; + +// How to truly clear a container: +class Foo { ... }; +vector<Foo> v; +for (int i = 0; i < 10; ++i) + v.push_back(Foo()); + +// Following line sets size of v to 0, but destructors don't get called, +// and resources aren't released! +v.empty(); +v.push_back(Foo()); // New value is copied into the first Foo we inserted in the loop. + +// Truly destroys all values in v. See section about temporary object for +// explanation of why this works. +v.swap(vector<Foo>()); + ``` Further Reading: |