[/
Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
Copyright (c) 2019-2020 Krystian Stasiowski (sdkrystian at gmail dot com)
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Official repository: https://github.com/boostorg/static_string
]
[library Boost.StaticString
[id static_string]
[quickbook 1.6]
[copyright 2019 - 2020 Krystian Stasiowski]
[copyright 2016 - 2019 Vinnie Falco]
[purpose String Library]
[license
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
[@http://www.boost.org/LICENSE_1_0.txt])
]
[authors [Stasiowski, Krystian], [Falco, Vinnie]]
[category template]
[category generic]
]
[template mdash[] '''— ''']
[template indexterm1[term1] ''''''[term1]'''''']
[template indexterm2[term1 term2] ''''''[term1]''''''[term2]'''''']
[template path_link[path name] ''''''[name]'''''']
[template include_file[path][^<''''''[path]''''''>]]
[def __InputIterator__ [@https://en.cppreference.com/w/cpp/named_req/InputIterator ['InputIterator]]]
[/-----------------------------------------------------------------------------]
[heading Introduction]
This library provides a dynamically resizable string of characters with
compile-time fixed capacity and contiguous embedded storage in which the
characters are placed within the string object itself. Its API closely
resembles that of `std::string`.
[/-----------------------------------------------------------------------------]
[heading Motivation]
A fixed capacity string is useful when:
* Memory allocation is not possible, e.g., embedded environments without a free
store, where only a stack and the static memory segment are available.
* Memory allocation imposes an unacceptable performance penalty.
e.g., with respect to latency.
* Allocation of objects with complex lifetimes in the static-memory
segment is required.
* A dynamically-resizable string is required within `constexpr` functions.
* The storage location of the static_vector elements is required to be
within the string object itself (e.g. to support `memcpy` for serialization
purposes).
[/-----------------------------------------------------------------------------]
[heading Requirements]
The library is usable in two different modes: standalone and Boost dependent. This library defaults to Boost dependent mode; standalone mode is opt-in through the use of a configuration macro.
When in Boost dependent mode, the library requires the use of at least C++11, in addition to Boost.Core, Boost.Utility, and Boost.ContainerHash. In standalone mode, C++17 is required but no libraries except for the standard library are needed.
[/-----------------------------------------------------------------------------]
[heading Design]
The over-arching design goal is to resemble the interface and behavior of
`std::string` as much as possible. When any operation would exceed the
maximum allowed size of the string, `std::length_error` is thrown if exceptions are enabled. All
algorithms which throw exceptions provide the strong exception safety
guarantee. This is intended to be a drop in replacement for `std::string`.
The API of `static_string` only diverges from `std::string` in few places,
one of which is the addition of the `subview` function, for which this implementation
returns a string view instead of `static_string`,
and certain functions that will never throw are marked as `noexcept`, which diverges from
those of `std::string`. The available overloads for `static_string` are identical to those
of `std::string`.
[/-----------------------------------------------------------------------------]
[heading Iterators]
The iterator invalidation rules differ from those of `std::string`:
* Moving a `static_string` invalidates all iterators
* Swapping two `static_string`s invalidates all iterators
[/-----------------------------------------------------------------------------]
[heading Optimizations]
Depending on the character type and size used for a specialization of `static_string`, certain optimizations are used to reduce the size of the class type. Given the name of a specialization of the form `basic_static_string`:
* If `N` is 0, then the class has no non-static data members. Given two objects `a` and `b` of type `basic_static_string<0, T, Traits>` and `static_string<0, U, Traits>` respectively, the pointer value returned by `data()` will be the same if `T` and `U` are the same.
* Otherwise, the type of the member used to store the size of the `static_string` will be the smallest standard unsigned integer type that can represent the value `N`.
[/-----------------------------------------------------------------------------]
[heading Configuration]
Certain features can be enabled and disabled though defining configuration macros. The macros and the associated feature they control are:
* `BOOST_STATIC_STRING_STANDALONE`: When defined, the library is put into standalone mode.
[/-----------------------------------------------------------------------------]
[heading Acknowledgments]
Thanks to [@https://github.com/K-ballo Agustín Bergé], [@https://github.com/pdimov Peter Dimov], [@https://github.com/glenfe Glen Fernandes], and [@https://github.com/LeonineKing1199 Christian Mazakas] for their constant feedback and guidance during the development of this library.
The development of this library is sponsored by [@https://cppalliance.org The C++ Alliance].
[/-----------------------------------------------------------------------------]
[heading Reference]
Defined in namespace `boost::static_strings`:
[link static_string.ref.boost__static_strings__basic_static_string `basic_static_string`]
[/-----------------------------------------------------------------------------]
[section:ref Reference]
[include reference.qbk]
[endsect]
[/-----------------------------------------------------------------------------]
[xinclude index.xml]