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https://github.com/triqs/dft_tools
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44 lines
1.9 KiB
ReStructuredText
44 lines
1.9 KiB
ReStructuredText
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C++11/14 & notations
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=====================
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C++11/C++14
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---------------
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TRIQS is a C++11 library. It *requires* a last generation C++ compiler (Cf :ref:`require_cxx_compilers`).
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Indeed, the development of C++ is very dynamic these years.
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The language and its usage is changing very profoundly with the introduction of several
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notions (e.g. move semantics, type deduction, lambda, variadic templates ...).
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Moreover, C++11 compliant compilers are now widely available, with gcc and clang.
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A major consequence of this evolution is that writing libraries
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has become much more accessible, at a *much* lower cost in development time,
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with clearer, shorter and more readable code, hence maintainable.
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Efficient techniques which were considered before as complex and reserved to professional C++ experts
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are now becoming simple to implement, like e.g. expression templates.
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The implementation of most of the TRIQS library (e.g. clef, arrays) would be either impossible or at least
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much more complex and time consuming (with a lot of abstruse boost-like construction)
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in previous versions of C++.
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Besides, this evolution is not finished.
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The new coming standard, C++14, expected to be adopted and implemented very soon,
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will still make it a lot better. In particular, the concept support (template constraints)
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will hopefully solve the most problematic issue with metaprogramming techniques, i.e. the lack of concept
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check at compile time, resulting in long and obscur error messages from the compiler when *using* the library.
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Hence, TRIQS will move to C++14 as soon as compilers are available.
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Notation
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----------
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In the documentation, we make use in particular of the C++14 concept notation for template.
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For example ::
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template<ImmutableArray A> void f(A const & a);
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means that f is a template ::
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template<typename A> void f(A const & a);
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which is enabled or valid only for types A which models the `ImmutableArray` concept.
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