You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
118 lines
5.7 KiB
HTML
118 lines
5.7 KiB
HTML
4 years ago
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>Deprecated Features - Using the GNU Compiler Collection (GCC)</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Using the GNU Compiler Collection (GCC)">
|
||
|
|
<meta name="generator" content="makeinfo 4.13">
|
||
|
|
<link title="Top" rel="start" href="index.html#Top">
|
||
|
|
<link rel="up" href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" title="C++ Extensions">
|
||
|
|
<link rel="prev" href="Java-Exceptions.html#Java-Exceptions" title="Java Exceptions">
|
||
|
|
<link rel="next" href="Backwards-Compatibility.html#Backwards-Compatibility" title="Backwards Compatibility">
|
||
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
||
|
|
<!--
|
||
|
|
Copyright (C) 1988-2015 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.-->
|
||
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
||
|
|
<style type="text/css"><!--
|
||
|
|
pre.display { font-family:inherit }
|
||
|
|
pre.format { font-family:inherit }
|
||
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallexample { font-size:smaller }
|
||
|
|
pre.smalllisp { font-size:smaller }
|
||
|
|
span.sc { font-variant:small-caps }
|
||
|
|
span.roman { font-family:serif; font-weight:normal; }
|
||
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="node">
|
||
|
|
<a name="Deprecated-Features"></a>
|
||
|
|
<p>
|
||
|
|
Next: <a rel="next" accesskey="n" href="Backwards-Compatibility.html#Backwards-Compatibility">Backwards Compatibility</a>,
|
||
|
|
Previous: <a rel="previous" accesskey="p" href="Java-Exceptions.html#Java-Exceptions">Java Exceptions</a>,
|
||
|
|
Up: <a rel="up" accesskey="u" href="C_002b_002b-Extensions.html#C_002b_002b-Extensions">C++ Extensions</a>
|
||
|
|
<hr>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<h3 class="section">7.12 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>While the list below is not exhaustive, it documents some of the options
|
||
|
|
that are now deprecated:
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><code>-fexternal-templates</code><dt><code>-falt-external-templates</code><dd>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.
|
||
|
|
|
||
|
|
<br><dt><code>-fstrict-prototype</code><dt><code>-fno-strict-prototype</code><dd>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>.
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>G++ allows a virtual function returning ‘<samp><span class="samp">void *</span></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>The G++ minimum and maximum operators (‘<samp><span class="samp"><?</span></samp>’ and ‘<samp><span class="samp">>?</span></samp>’) and
|
||
|
|
their compound forms (‘<samp><span class="samp"><?=</span></samp>’) and ‘<samp><span class="samp">>?=</span></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>The named return value extension has been deprecated, and is now
|
||
|
|
removed from G++.
|
||
|
|
|
||
|
|
<p>The use of initializer lists with new expressions has been deprecated,
|
||
|
|
and is now removed from G++.
|
||
|
|
|
||
|
|
<p>Floating and complex non-type template parameters have been deprecated,
|
||
|
|
and are now removed from G++.
|
||
|
|
|
||
|
|
<p>The implicit typename extension has been deprecated and is now
|
||
|
|
removed from G++.
|
||
|
|
|
||
|
|
<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>G++ allows floating-point literals to appear in integral constant expressions,
|
||
|
|
e.g. ‘<samp><span class="samp"> enum E { e = int(2.2 * 3.7) } </span></samp>’
|
||
|
|
This extension is deprecated and will be removed from a future version.
|
||
|
|
|
||
|
|
<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.
|
||
|
|
|
||
|
|
</body></html>
|
||
|
|
|