How Can I Efficiently Initialize std::vectors in C ?

Initializing std::vectors with Simplicity: A Swift Approach

In the realm of programming, it's often desirable to initialize data structures with specific values. The std::vector, a ubiquitous container in C , offers an elegant solution for such scenarios.

The Traditional Method

As mentioned in the query, one traditional method of initializing a std::vector is through the append-and-assign approach:

std::vector<int> ints;
ints.push_back(10);
ints.push_back(20);
ints.push_back(30);

While functional, this process involves multiple steps and can become tedious for sizeable collections.

Swift Initialization with C 11

C 11 introduced a significant enhancement, simplifying vector initialization through braced initialization:

std::vector<int> v = {1, 2, 3, 4};

This syntax provides an intuitive and straightforward way to initialize vectors with hardcoded elements, eliminating the need for explicit element addition.

Alternative Options with Boost

In case your compiler does not support C 11, the Boost.Assign library offers alternative methods:

List-of Constructor:

#include <boost/assign/list_of.hpp>
...
std::vector<int> v = boost::assign::list_of(1)(2)(3)(4);

std Namespace Extension:

#include <boost/assign/std/vector.hpp>
using namespace boost::assign;
...
std::vector<int> v;
v += 1, 2, 3, 4;

It's worth noting that these Boost options may incur performance overhead due to underlying deque construction. For performance-sensitive code, using the traditional push_back approach would be advisable.

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