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Krystian Stasiowski
64 lines
4.7 KiB
Markdown
64 lines
4.7 KiB
Markdown
# Boost.FixedString
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Branch | Travis | Appveyor | Azure Pipelines | codecov.io | Docs | Matrix |
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:-------------: | ------ | -------- | --------------- | ---------- | ---- | ------ |
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[`master`](https://github.com/vinniefalco/fixed_string/tree/master) | [](https://travis-ci.org/vinniefalco/fixed_string) | [](https://ci.appveyor.com/project/vinniefalco/fixed-string/branch/master) | [](https://dev.azure.com/vinniefalco/fixed-string/_build/latest?definitionId=6&branchName=master) | [](https://codecov.io/gh/vinniefalco/fixed_string/branch/master) | [](http://www.boost.org/doc/libs/master/doc/html/fixed_string.html) | [](http://www.boost.org/development/tests/master/developer/fixed_string.html)
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[`develop`](https://github.com/vinniefalco/fixed_string/tree/develop) | [](https://travis-ci.org/vinniefalco/fixed_string) | [](https://ci.appveyor.com/project/vinniefalco/fixed-string/branch/develop) | [](https://dev.azure.com/vinniefalco/fixed-string/_build/latest?definitionId=6&branchName=master) | [](https://codecov.io/gh/vinniefalco/fixed_string/branch/develop) | [](http://www.boost.org/doc/libs/develop/doc/html/fixed_string.html) | [](http://www.boost.org/development/tests/develop/developer/fixed_string.html)
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## This is currently **NOT** an official Boost library.
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## Introduction
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This library provides a dynamically resizable string of characters with
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compile-time fixed capacity and contiguous embedded storage in which the
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characters are placed within the string object itself. Its API closely
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resembles that of `std::string`
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## Motivation
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A fixed capacity string is useful when:
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* Memory allocation is not possible, e.g., embedded environments without a free
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store, where only a stack and the static memory segment are available.
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* Memory allocation imposes an unacceptable performance penalty.
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e.g., with respect to latency.
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* Allocation of objects with complex lifetimes in the static-memory
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segment is required.
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* A dynamically-resizable string is required within `constexpr` functions.
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* The storage location of the static_vector elements is required to be
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within the string object itself (e.g. to support `memcpy` for serialization
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purposes).
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## Design
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The over-arching design goal is to resemble the interface and behavior of
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`std::string` as much as possible. When any operation would exceed the
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maximum allowed size of the string, `std::length_error` is thrown. All
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algorithms which throw exceptions provide the strong exception safety
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guarantee. This is intended to be a drop in replacement for `std::string`.
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All the operations for `fixed_string` work when the source is within the string itself.
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The API of `fixed_string` only diverges from `std::string` in few places,
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being `substr` for which this implementation returns a string view instead of `fixed_string,
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and certain functions that will never throw are marked as `noexcept`, which diverges from
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those of `std::string`. Every function that is in the C++20 specification of `std::string` is
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present in this implementation, with the only difference being the lack of `constexpr`
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for the time being. The avaliable overloads for `fixed_string` are identical to those
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of `std::string`, except for `operator+` which is explicitly deleted as no reasonable implementation
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would be possible, due to the difficulty in determining the size of the resulting `fixed_string`.
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## Iterators
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The iterator invalidation rules are different than those for `std::string`,
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since:
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* Moving a string invalidates all iterators
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* Swapping two strings invalidates all iterators
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## License
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file [LICENSE_1_0.txt](LICENSE_1_0.txt) or copy at
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https://www.boost.org/LICENSE_1_0.txt)
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