使用隐式函数模板特化来检查标识符是否是数组 [英] Using implicit function template specialization to check if an identifier is an array
问题描述
我正在考虑使用函数模板来验证
标识符是否为数组类型。可以使用以下模板
用于此目的：
模板< typename T，int N>
void check_array（T（&）[N]）
{
}
那么使用size_t而不是int呢？
-
[见 http://www.gotw.ca/resources/clcm.htm 有关的信息]
[ comp.lang.c ++。主持。第一次海报：做到这一点！ ]
I''m thinking about using a function tamplate to verify that an
identifier is of an array type. May the following template be
used for this purpose:
template< typename T, int N >
void check_array( T(&)[N] )
{
}
And what about using size_t instead of int?
--
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
[ comp.lang.c++.moderated. First time posters: Do this! ]
推荐答案
[我在clc ++中删除了交叉发布。这样文章就会更早出现]
Angel Tsankov写道：
[ I dropped cross-posting in c.l.c++.m so the articles appear sooner]
Angel Tsankov wrote:
我正在考虑使用函数模板来验证
标识符是否属于数组类型。可以使用以下模板
用于此目的：
模板< typename T，int N>
void check_array（T（&）[N]）
{
}
那么使用size_t而不是int呢？
I''m thinking about using a function tamplate to verify that an
identifier is of an array type. May the following template be
used for this purpose:
template< typename T, int N >
void check_array( T(&)[N] )
{
}
And what about using size_t instead of int?
是的，我可能会使用''size_t''，虽然''int''几乎可以使用
，如果大小小于INT_MAX。
或许将它与编译时断言相结合将会更好，并且你可以尝试加入一个不错的错误
消息进入它，但应该开箱即用......
你为什么这么问？你遇到任何问题吗？
V
-
请删除大写''A'时通过电子邮件回复
我没有回复最热门的回复，请不要问
Yes, I''d probably use ''size_t'', although ''int'' would work almost
as well if the size is less than INT_MAX.
Perhaps incorporating this with a compile-time assert would be
a bit better, and you could try incorporating a decent error
message into it, but should work right out of the box...
Why do you ask? Have you run into any problem with it?
V
--
Please remove capital ''A''s when replying by e-mail
I do not respond to top-posted replies, please don''t ask
Angel Tsankov schrieb：
Angel Tsankov schrieb:
我正在考虑使用函数tamplate来验证
标识符是否为数组类型。可以使用以下模板
用于此目的：
模板< typename T，int N>
void check_array（T（&）[N]）
{
}
I''m thinking about using a function tamplate to verify that an
identifier is of an array type. May the following template be
used for this purpose:
template< typename T, int N >
void check_array( T(&)[N] )
{
}
是的，绝对。
Yes, absolutely.
那么使用size_t而不是int呢？
And what about using size_t instead of int?
确实size_t是这种方法的规范类型，因为它是
unsigned，因为每个静态可创建的数组必须有一个
尺寸可通过sizeof表示，其本身返回size_t。
来自不来梅的问候，
DanielKrügler
-
[见 http：/ /www.gotw.ca/resources/clcm.htm 了解有关的信息]
[comp.lang.c ++。moderated。第一次海报：做到这一点！ ]
Indeed size_t is the canonical type for this approach, because it is
unsigned and because every statically creatable array must have a
size expressable via sizeof, which itself returns size_t.
Greetings from Bremen,
Daniel Krügler
--
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
[ comp.lang.c++.moderated. First time posters: Do this! ]
> [我在clc ++。m中删除了交叉发布，因此文章显示为
>[ I dropped cross-posting in c.l.c++.m so the articles appear
>更快]
Angel Tsankov写道：
>sooner]
Angel Tsankov wrote:
>我正在考虑使用一个函数tamplate以验证
标识符是否为数组类型。可以将以下模板用于此目的：
模板< typename T，int N>
void check_array（T（&）[N]）
{
}
那么使用size_t而不是int呢？
>I''m thinking about using a function tamplate to verify that an
identifier is of an array type. May the following template be
used for this purpose:
template< typename T, int N >
void check_array( T(&)[N] )
{
}
And what about using size_t instead of int?
是的，我可能会使用''size_t''，虽然''int''可以使用
几乎
如果大小小于INT_MAX。
或许将其与编译时断言相结合将是
a更好，
Yes, I''d probably use ''size_t'', although ''int'' would work
almost
as well if the size is less than INT_MAX.
Perhaps incorporating this with a compile-time assert would be
a bit better,
你的想法是什么？
What is your idea?
你可以尝试加入一个体面的错误
消息进入它，但应该开箱即用...
and you could try incorporating a decent error
message into it, but should work right out of the box...
是否有标准方法来合并错误消息？
Is there a standard way to incorporate an error message?
你为什么这么问？你遇到任何问题吗？
Why do you ask? Have you run into any problem with it?
不，我没有发现任何问题。我只是好奇，如果
它是可靠的，那就是模板是否应该隐式地实例化，当且仅当参数属于数组类型时才会实例化。
No, I have not found any problems with it. I am just curious if
it is reliable, that is whether the template shall be implicitly
instantiated if and only if the argument is of an array type.
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