A non-owning reference to a null-terminated part of a string
TL;DR: mpt::zstring_view extends the benefits of
std::string_view to code that requires strings that are
null-terminated. For full documentation, see the docs/ directory.
The introduction of std::string_view into C++ provides a better way
to pass around non-owning references to (parts of) strings. For
example, it can return its length in O(1) time, compared to O(N)
with bare pointers. It avoids the need to create unnecessary
temporaries that can occur when using const std::string&s but still
supports a number of useful operations as methods and operator
overloads.
For more on the rationale and design of std::string_view, see
proposal N3762 or the cppreference.com page on
std::basic_string_view.
However, std::string_view does not require the (sub-)string to
which it refers to be null-terminated. In fact, in order to support
some operations (substr() and remove_suffix(), particularly), it
cannot. This prevents its use in several places where it might
otherwise be useful.
Many C APIs, and C++ code that interacts with them, need to be passed
null-terminated strings. As std::string_view cannot be used, we are
back to passing around bare pointers or const std::string&s and
potentially requiring unnecessary copies. Either that, or we must
write several overloads of functions that do the same thing but with
different string representations.
This is where mpt::zstring_view comes in. It can only be constructed
from a null-terminated string of some kind, and allows only operations
that preserve that property. It can also be implicitly cast to a plain
std::string_view, and operations that cause null-termination to be
potentially sacrificed also return std::string_views.
zstring_view is a header only library (and will remain so, even when
more files are introduced). Simply include the repository path in your
project's include path and include zstring_view.hpp where required.
All code in the project is licensed under the Apache License 2.0. A
full copy of the license document is provided in LICENSE.txt. All
project documentation is licensed under the GNU Free Documentation
License, a copy of which is provided in docs/LICENSE.txt. Much of
this is based on content from the cppreference.com wiki, whose
information is often helpful and is much appreciated.