stl Archives - Page 4 of 6

Why use iterators instead of array indices?

Take the following two lines of code: for (int i = 0; i < some_vector.size(); i++) { //do stuff } And this: for ...

May 20, 2022
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Is std::unique_ptr required to know the full definition of T?

I have some code in a header that looks like this: #include <memory> class Thing; class MyClass { std::unique_ptr< Thing > my_thing; }; ...

May 18, 2022
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Determine if map contains a value for a key?

What is the best way to determine if a STL map contains a value for a given key? #include <map> using namespace std; ...

May 17, 2022
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How to retrieve all keys (or values) from a std::map and put them into a vector?

This is one of the possible ways I come out: struct RetrieveKey { template <typename T> typename T::first_type operator()(T keyValuePair) const { return ...

May 16, 2022
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Sorting a vector of custom objects

How does one go about sorting a vector containing custom (i.e. user defined) objects. Probably, standard STL algorithm sort along with a predicate ...

May 16, 2022
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How to sum up elements of a C++ vector?

What are the good ways of finding the sum of all the elements in a std::vector? Suppose I have a vector std::vector<int> vector ...

May 16, 2022
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C++ Erase vector element by value rather than by position? [duplicate]

This question already has answers here: How do I remove an item from a stl vector with a certain value? (11 answers) Closed ...

May 15, 2022
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std::string length() and size() member functions

I was reading the answers for this question and found that there is actually a method called length() for std::string (I always used ...

May 15, 2022
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What’s the most efficient way to erase duplicates and sort a vector?

I need to take a C++ vector with potentially a lot of elements, erase duplicates, and sort it. I currently have the below ...

May 13, 2022
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