/Src/Dependencies/Boost/doc/test/array2.xml
http://hadesmem.googlecode.com/ · XML · 82 lines · 70 code · 12 blank · 0 comment · 0 complexity · a4721f4b34352cd4af9ba68b544a77f0 MD5 · raw file
- <section id="array.rationale">
- <title>Design Rationale</title>
- <para>
- There was an important design tradeoff regarding the
- constructors: We could implement array as an "aggregate" (see
- Section 8.5.1, [dcl.init.aggr], of the C++ Standard). This would
- mean:
- <itemizedlist>
- <listitem>
- <simpara>
- An array can be initialized with a
- brace-enclosing, comma-separated list of initializers for the
- elements of the container, written in increasing subscript
- order:
- </simpara>
- <programlisting>
- <classname>boost::array</classname><int,4> a = { { 1, 2, 3 } };
- </programlisting>
- <simpara>
- Note that if there are fewer elements in the
- initializer list, then each remaining element gets
- default-initialized (thus, it has a defined value).
- </simpara>
- </listitem>
- </itemizedlist>
- </para>
- <para>
- However, this approach has its drawbacks: <emphasis
- role="bold">
- passing no initializer list means that the elements
- have an indetermined initial value
- </emphasis>, because the rule says
- that aggregates may have:
- <itemizedlist>
- <listitem>
- <simpara>No user-declared constructors.</simpara>
- </listitem>
- <listitem>
- <simpara>No private or protected non-static data members.</simpara>
- </listitem>
- <listitem>
- <simpara>No base classes.</simpara>
- </listitem>
- <listitem>
- <simpara>No virtual functions.</simpara>
- </listitem>
- </itemizedlist>
- </para>
- <para>Nevertheless, The current implementation uses this approach.</para>
- <para>
- Note that for standard conforming compilers it is possible to
- use fewer braces (according to 8.5.1 (11) of the Standard). That is,
- you can initialize an array as follows:
- </para>
- <programlisting>
- <classname>boost::array</classname><int,4> a = { 1, 2, 3 };
- </programlisting>
- <para>
- I'd appreciate any constructive feedback. <emphasis
- role="bold">
- Please note: I don't have time to read all boost
- mails. Thus, to make sure that feedback arrives to me, please send
- me a copy of each mail regarding this class.
- </emphasis>
- </para>
- <para>
- The code is provided "as is" without expressed or implied
- warranty.
- </para>
- </section>