155 lines
7.4 KiB
HTML
155 lines
7.4 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1988-2016 Free Software Foundation, Inc.
|
|
|
|
Permission is granted to copy, distribute and/or modify this document
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
|
any later version published by the Free Software Foundation; with the
|
|
Invariant Sections being "Funding Free Software", the Front-Cover
|
|
Texts being (a) (see below), and with the Back-Cover Texts being (b)
|
|
(see below). A copy of the license is included in the section entitled
|
|
"GNU Free Documentation License".
|
|
|
|
(a) The FSF's Front-Cover Text is:
|
|
|
|
A GNU Manual
|
|
|
|
(b) The FSF's Back-Cover Text is:
|
|
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
|
software. Copies published by the Free Software Foundation raise
|
|
funds for GNU development. -->
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>Using the GNU Compiler Collection (GCC): Deprecated Features</title>
|
|
|
|
<meta name="description" content="Using the GNU Compiler Collection (GCC): Deprecated Features">
|
|
<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Deprecated Features">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<link href="index.html#Top" rel="start" title="Top">
|
|
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" rel="up" title="C++ Extensions">
|
|
<link href="Backwards-Compatibility.html#Backwards-Compatibility" rel="next" title="Backwards Compatibility">
|
|
<link href="Java-Exceptions.html#Java-Exceptions" rel="prev" title="Java Exceptions">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.smallquotation {font-size: smaller}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.indentedblock {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
div.smalldisplay {margin-left: 3.2em}
|
|
div.smallexample {margin-left: 3.2em}
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
|
div.smalllisp {margin-left: 3.2em}
|
|
kbd {font-style:oblique}
|
|
pre.display {font-family: inherit}
|
|
pre.format {font-family: inherit}
|
|
pre.menu-comment {font-family: serif}
|
|
pre.menu-preformatted {font-family: serif}
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
|
pre.smallexample {font-size: smaller}
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
|
pre.smalllisp {font-size: smaller}
|
|
span.nocodebreak {white-space:nowrap}
|
|
span.nolinebreak {white-space:nowrap}
|
|
span.roman {font-family:serif; font-weight:normal}
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
|
<a name="Deprecated-Features"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Backwards-Compatibility.html#Backwards-Compatibility" accesskey="n" rel="next">Backwards Compatibility</a>, Previous: <a href="Java-Exceptions.html#Java-Exceptions" accesskey="p" rel="prev">Java Exceptions</a>, Up: <a href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" accesskey="u" rel="up">C++ Extensions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
<hr>
|
|
<a name="Deprecated-Features-1"></a>
|
|
<h3 class="section">7.13 Deprecated Features</h3>
|
|
|
|
<p>In the past, the GNU C++ compiler was extended to experiment with new
|
|
features, at a time when the C++ language was still evolving. Now that
|
|
the C++ standard is complete, some of those features are superseded by
|
|
superior alternatives. Using the old features might cause a warning in
|
|
some cases that the feature will be dropped in the future. In other
|
|
cases, the feature might be gone already.
|
|
</p>
|
|
<p>While the list below is not exhaustive, it documents some of the options
|
|
that are now deprecated:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><code>-fexternal-templates</code></dt>
|
|
<dt><code>-falt-external-templates</code></dt>
|
|
<dd><p>These are two of the many ways for G++ to implement template
|
|
instantiation. See <a href="Template-Instantiation.html#Template-Instantiation">Template Instantiation</a>. The C++ standard clearly
|
|
defines how template definitions have to be organized across
|
|
implementation units. G++ has an implicit instantiation mechanism that
|
|
should work just fine for standard-conforming code.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-fstrict-prototype</code></dt>
|
|
<dt><code>-fno-strict-prototype</code></dt>
|
|
<dd><p>Previously it was possible to use an empty prototype parameter list to
|
|
indicate an unspecified number of parameters (like C), rather than no
|
|
parameters, as C++ demands. This feature has been removed, except where
|
|
it is required for backwards compatibility. See <a href="Backwards-Compatibility.html#Backwards-Compatibility">Backwards Compatibility</a>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>G++ allows a virtual function returning ‘<samp>void *</samp>’ to be overridden
|
|
by one returning a different pointer type. This extension to the
|
|
covariant return type rules is now deprecated and will be removed from a
|
|
future version.
|
|
</p>
|
|
<p>The G++ minimum and maximum operators (‘<samp><?</samp>’ and ‘<samp>>?</samp>’) and
|
|
their compound forms (‘<samp><?=</samp>’) and ‘<samp>>?=</samp>’) have been deprecated
|
|
and are now removed from G++. Code using these operators should be
|
|
modified to use <code>std::min</code> and <code>std::max</code> instead.
|
|
</p>
|
|
<p>The named return value extension has been deprecated, and is now
|
|
removed from G++.
|
|
</p>
|
|
<p>The use of initializer lists with new expressions has been deprecated,
|
|
and is now removed from G++.
|
|
</p>
|
|
<p>Floating and complex non-type template parameters have been deprecated,
|
|
and are now removed from G++.
|
|
</p>
|
|
<p>The implicit typename extension has been deprecated and is now
|
|
removed from G++.
|
|
</p>
|
|
<p>The use of default arguments in function pointers, function typedefs
|
|
and other places where they are not permitted by the standard is
|
|
deprecated and will be removed from a future version of G++.
|
|
</p>
|
|
<p>G++ allows floating-point literals to appear in integral constant expressions,
|
|
e.g. ‘<samp> enum E { e = int(2.2 * 3.7) } </samp>’
|
|
This extension is deprecated and will be removed from a future version.
|
|
</p>
|
|
<p>G++ allows static data members of const floating-point type to be declared
|
|
with an initializer in a class definition. The standard only allows
|
|
initializers for static members of const integral types and const
|
|
enumeration types so this extension has been deprecated and will be removed
|
|
from a future version.
|
|
</p>
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Backwards-Compatibility.html#Backwards-Compatibility" accesskey="n" rel="next">Backwards Compatibility</a>, Previous: <a href="Java-Exceptions.html#Java-Exceptions" accesskey="p" rel="prev">Java Exceptions</a>, Up: <a href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" accesskey="u" rel="up">C++ Extensions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|