Boost.Unordered: Part of collection of the Boost C++ Libraries.

Boost.Unordered

Part of collection of the Boost C++ Libraries.

For accessing data based on key lookup, the C++ standard library offers std::set, std::map, std::multiset and std::multimap. These are generally implemented using balanced binary trees so that lookup time has logarithmic complexity. That is generally okay, but in many cases a hash table can perform better, as accessing data has constant complexity, on average. The worst case complexity is linear, but that occurs rarely and with some care, can be avoided.

Also, the existing containers require a 'less than' comparison object to order their elements. For some data types this is impossible to implement or isn’t practical. In contrast, a hash table only needs an equality function and a hash function for the key.

With this in mind, unordered associative containers were added to the C++ standard. This is an implementation of the containers described in C++11, with some deviations from the standard in order to work with non-C++11 compilers and libraries.

License

Distributed under the Boost Software License, Version 1.0.

Properties

• C++03
• Header-Only

Build Status

Branch	GH Actions	Appveyor	codecov.io	Deps	Docs	Tests
master
develop

Directories

Name	Purpose
doc	documentation
example	examples
include	headers
test	unit tests

More information

• Ask questions
• Report bugs: Be sure to mention Boost version, platform and compiler you're using. A small compilable code sample to reproduce the problem is always good as well.
• Submit your patches as pull requests against develop branch. Note that by submitting patches you agree to license your modifications under the Boost Software License, Version 1.0.
• Discussions about the library are held on the Boost developers mailing list. Be sure to read the discussion policy before posting and add the [unordered] tag at the beginning of the subject line.

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Author: boostorg
Source code: https://github.com/boostorg/unordered
License: BSL-1.0 license

#cpluplus 

What is GEEK

Buddha Community

Collection vs Collections in Java: Difference Between Collection & Collections in Java

Introduction

This article will be looking into one of the most popular questions in Java Language – What is Collection in Java? Also, what do you mean by Collections in Java? Are Collection and Collections the same or different in Java?

What is Collection?

What is Collections?

Conclusion

#full stack development #collection #collection vs collections in java #collections in java #difference between collection and collections in java

How to Run C/C++ in Sublime Text?

C and C++ are the most powerful programming language in the world. Most of the super fast and complex libraries and algorithms are written in C or C++. Most powerful Kernel programs are also written in C. So, there is no way to skip it.

In programming competitions, most programmers prefer to write code in C or C++. Tourist is considered the worlds top programming contestant of all ages who write code in C++.

During programming competitions, programmers prefer to use a lightweight editor to focus on coding and algorithm designing. Vim, Sublime Text, and Notepad++ are the most common editors for us. Apart from the competition, many software developers and professionals love to use Sublime Text just because of its flexibility.

I have discussed the steps we need to complete in this blog post before running a C/C++ code in Sublime Text. We will take the inputs from an input file and print outputs to an output file without using freopen file related functions in C/C++.

#cpp #c #c-programming #sublimetext #c++ #c/c++

Dicey Issues in C/C++

If you are familiar with C/C++then you must have come across some unusual things and if you haven’t, then you are about to. The below codes are checked twice before adding, so feel free to share this article with your friends. The following displays some of the issues:

1. Using multiple variables in the print function
2. Comparing Signed integer with unsigned integer
3. Putting a semicolon at the end of the loop statement
4. C preprocessor doesn’t need a semicolon
5. Size of the string matters
6. Macros and equations aren’t good friends
7. Never compare Floating data type with double data type
8. Arrays have a boundary
9. Character constants are different from string literals
10. Difference between single(=) and double(==) equal signs.

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The below code generates no error since a print function can take any number of inputs but creates a mismatch with the variables. The print function is used to display characters, strings, integers, float, octal, and hexadecimal values onto the output screen. The format specifier is used to display the value of a variable.

1. %d indicates Integer Format Specifier
2. %f indicates Float Format Specifier
3. %c indicates Character Format Specifier
4. %s indicates String Format Specifier
5. %u indicates Unsigned Integer Format Specifier
6. %ld indicates Long Int Format Specifier

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A signed integer is a 32-bit datum that encodes an integer in the range [-2147483648 to 2147483647]. An unsigned integer is a 32-bit datum that encodes a non-negative integer in the range [0 to 4294967295]. The signed integer is represented in twos-complement notation. In the below code the signed integer will be converted to the maximum unsigned integer then compared with the unsigned integer.

#problems-with-c #dicey-issues-in-c #c-programming #c++ #c #cplusplus

Introduction to C++ Programming Language | C++ Tutorial for Beginners - Part 1

This Edureka video on Introduction to C++ Programming will help you to get started with C++. It will cover all the fundamental concepts which will help you in gaining a better understanding over the technology.

#c #c# #c++ #programming-c

Boost.GIL: Generic Image Library | Requires C++14 Since Boost 1.80

 

Documentation	GitHub Actions	AppVeyor	Azure Pipelines	Regression	Codecov

Boost.GIL

• Introduction
• Documentation
• Requirements
• Branches
• Community
• Contributing
• License

Introduction

Boost.GIL is a part of the Boost C++ Libraries.

The Boost Generic Image Library (GIL) is a C++14 header-only library that abstracts image representations from algorithms and allows writing code that can work on a variety of images with performance similar to hand-writing for a specific image type.

Documentation

• Latest release
• Branch master (latest release with minor changes)
• Branch develop

See RELEASES.md for release notes.

See CONTRIBUTING.md for instructions about how to build and run tests and examples using Boost.Build or CMake.

See example/README.md for GIL usage examples.

See example/b2/README.md for Boost.Build configuration examples.

See example/cmake/README.md for CMake configuration examples.

Requirements

The Boost Generic Image Library (GIL) requires:

• C++14 compiler (GCC 6, clang 3.9, MSVC++ 14.1 (1910) or any later version)
• Boost header-only libraries

Optionally, in order to build and run tests and examples:

• Boost.Filesystem
• Boost.Test
• Headers and libraries of libjpeg, libpng, libtiff, libraw for the I/O extension and some of examples.

Branches

The official repository contains the following branches:

master This holds the most recent snapshot with code that is known to be stable.

develop This holds the most recent snapshot. It may contain unstable code.

Community

There is number of communication channels to ask questions and discuss Boost.GIL issues:

• GitHub Discussions
• Mailing lists (Boost discussion policy)
  • boost-gil (recommended) official Boost.GIL mailing list (archive)
  • boost-users for all Boost users
  • boost for all Boost developers
• Slack at cpplang.slack.com with Boost channels:
  • #boost-gil (recommended) official Boost.GIL channel
  • #boost-user for all Boost users
  • #boost for all Boost developers
• Gitter room boostorg/gil (old real-time chat space)
• You can also ask questions via GitHub issue.

Contributing (We Need Your Help!)

If you would like to contribute to Boost.GIL, help us improve the library and maintain high quality, there is number of ways to do it.

If you would like to test the library, contribute new feature or a bug fix, see the CONTRIBUTING.md where the whole development infrastructure and the contributing workflow is explained in details.

You may consider performing code reviews on active pull requests or help with solving reported issues, especially those labelled with:

• status/need-help
• status/need-feedback
• need-minimal-example

Any feedback from users and developers, even simple questions about how things work or why they were done a certain way, carries value and can be used to improve the library.

License

Distributed under the Boost Software License, Version 1.0.

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Author:  boostorg
Source code: https://github.com/boostorg/gil
License: BSL-1.0 license

#cpluplus