benn/lumiera_
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

DOC: update the Boost-page to reflect what's part of the language now

Browse source 
several C++11 features used to be Boost features in the past
This commit is contained in:
Fischlurch 2014-08-16 00:03:32 +02:00
parent e205e1e1a0
commit 50faee12b3
1 changed files with 26 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

39
doc/technical/howto/UsingBoost.txt
View file

@ -1,7 +1,7 @@
Using Boost Libraries
=====================
//Menu: label using boost
//Menu: label using Boost
_some arbitrary hints and notes regarding the use of link::http://www.boost.org[Boost Libraries] in Lumiera_
@ -12,11 +12,19 @@ those features, as we're using them heavily throughout our code base. As it stan
are quite lacking and outdated, compared with today's programming standards. To fill some of these gaps
and to compensate for compiler deficiencies, some members of the C\++ committee and generally very
knowledgeable programmers created a set of C\++ libraries generally known as *Boost*. Some of these
especially worthy additions are also proposed for inclusion into the C++ standard library.
especially worthy additions were proposed and subsequently included into the new C++11 standard.
C++11 Features
~~~~~~~~~~~~~~
In Lumiera, we heavily rely on some features proposed and matured in the Boost libraries,
and meanwhile included in the current language standard. These features are thus now provided
through the standard library accompanying the compiler. For sake of completeness, we'll mention
them here. In the past _we used the Boost-Implementation_ of these facilities, but we don't need
Boost for this purpose anymore.
.memory
The `<boost/memory.hpp>` rsp. `<tr1/memory>` libraries define a family of smart-pointers to serve
several needs of basic memory management. In almost all cases, they're superior to using `std::auto_ptr`. +
The `<memory>` libraries (formerly `<boost/memory.hpp>` rsp. `<tr1/memory>`) define a family of smart-pointers
to serve several needs of basic memory management. In almost all cases, they're superior to using `std::auto_ptr`. +
When carefully combining these nifty templates with the RAII pattern, most concerns for memory
management, clean-up and error handling simply go away. (but please understand how to avoid
circular references and care for the implications of parallelism though)
@ -30,11 +38,22 @@ concepts might be mind bending at start, but it's certainly worth the effort (in
productivity)
.hashtables and hash functions
The `unordered_*` collection types amend a painful omission in the STL. The `functional_hash` library
supplements hash function for the primitive types and a lot of standard constructs using the STL; moreover
there is an extension point for using custom types in those hashtables
The `unordered_*` collection types amend a painful omission in the STL. To work properly, these collection
implementations need a way to calculate a _hash value_ for every key (rsp. entry in case of the Set-container).
The hash function to use can be defined as additional parameter; there are also some conventions to pick a
hash function automatically. Currently (2014), we have two options for the hash function implementation:
The `std::hash` or the `boost::hash` implementation.
(-> read more link:HashFunctions.html[here...])
.STATIC_ASSERT
a helper to check and enforce some conditions regarding types _at compile time_.
In case of assertion failure a compilation error is provoked, which should at least give a clue
towards the real problem guarded by the static assertion. It is good practice to place an extended
source code comment near the static assertion statement to help solving the actual issue.
Relevant Bosst extensions
~~~~~~~~~~~~~~~~~~~~~~~~~
.noncopyable
Inheriting from `boost::noncoypable` inhibits any copy, assignment and copy construction. It's a highly
recommended practice _by default to use that for every new class you create_ -- unless you know for sure
@ -54,12 +73,6 @@ code generation, based on some type traits or other (metaprogramming) predicates
since C++ is lacking introspection features, we're frequently forced to resort to metaprogramming
techniques, i.e to influence the way the compiler translates our code from within that very code.
.STATIC_ASSERT
a helper to check and enforce some conditions regarding types _at compile time_.
Because there is no support for this feature by the compiler, in case of assertion failure
a compilation error is provoked, trying to give at least a clue to the real problem by
creative use of variable names printed in the compiler's error message.
.metaprogramming library
A very elaborate, and sometimes mind-bending library and framework. While heavily used within
Boost to build the more advanced features, it seems too complicated and esoteric for general purpose