std :: map关联容器问题 [英] std::map associative container question
问题描述
大家好，
我想知道是否有办法使用std :: map来存储
不同的类型之一它的两种类型。也就是说，我正在尝试使用
它作为：
typedef std :: map< string，doubleMap;
但不是双倍，我有整数，甚至是布尔值，所以我猜这个使用双重浪费了很多存储空间。有没有办法做到这一点？
也许有一个姓名？
谢谢大家，
a ^ 2
Hello everyone,
I would like to know if there is a way to use the std::map to store
different types for one of its two types. That is, I''m trying to use
it as:
typedef std::map<string,doubleMap;
but instead of double, I have integers, even booleans so I guess that
the use of double waste a lot of storage. Is there any way to do this?
Maybe with a typename?
Thank you all,
a^2
推荐答案
aaragon写道：
aaragon wrote:
I想知道是否有办法使用std :: map来存储
两种类型之一的不同类型。也就是说，我正在尝试使用
它作为：
typedef std :: map< string，doubleMap;
但不是双倍，我有整数，甚至是布尔值，所以我猜这个使用双重浪费了很多存储空间。有没有办法做到这一点？
也许有一个打字机？
I would like to know if there is a way to use the std::map to store
different types for one of its two types. That is, I''m trying to use
it as:
typedef std::map<string,doubleMap;
but instead of double, I have integers, even booleans so I guess that
the use of double waste a lot of storage. Is there any way to do this?
Maybe with a typename?
看一下boost :: any。如果这没有帮助，你可能需要更多地描述你想要做的事情。顺便说一下，虽然我可以看到没有使用双打的充分理由，但为什么你要关心浪费
存储？地图真的那么大吗？
祝你好运，
Tom
Take a look at boost::any. If that''s no help, you may need to describe
a bit more what it is you are trying to do. By the way, although I can
see good reasons not to use doubles, why do you care about wasting
storage? Is the map really that big?
Best regards,
Tom
Thomas Tutone写道：
Thomas Tutone wrote:
aaragon写道：
aaragon wrote:
我想知道是否有办法使用std :: map存储
两种类型之一的不同类型。也就是说，我正在尝试使用
它作为：
typedef std :: map< string，doubleMap;
但不是双倍，我有整数，甚至是布尔值，所以我猜这个使用双重浪费了很多存储空间。有没有办法做到这一点？
也许有一个打字机？
I would like to know if there is a way to use the std::map to store
different types for one of its two types. That is, I''m trying to use
it as:
typedef std::map<string,doubleMap;
but instead of double, I have integers, even booleans so I guess that
the use of double waste a lot of storage. Is there any way to do this?
Maybe with a typename?
看一下boost :: any。如果这没有帮助，你可能需要更多地描述你想要做的事情。顺便说一下，虽然我可以看到没有使用双打的充分理由，但为什么你要关心浪费
存储？地图真的那么大吗？
祝你好运，
Tom
Take a look at boost::any. If that''s no help, you may need to describe
a bit more what it is you are trying to do. By the way, although I can
see good reasons not to use doubles, why do you care about wasting
storage? Is the map really that big?
Best regards,
Tom
$ b $嗯，不是地图很大，而且当你请求密钥时，
然后返回值。因此，有时候我会期待一个bool
但是我得到了一个双倍（我不想转换
值也不想放一个前面的说明符为（bool）例如）。我是b / b
想知道可能有一种神圣化的方式来做到这一点。对于
示例，
模板< typename T>
....
typedef std :: map< string，TMap;
但我认为它不会起作用.....
Well, it''s not that the map is big, but also when you request the key,
then the value is returned. Therefore, sometimes I''m expecting a bool
but instead I''m receiving a double (and I don''t want to convert the
values nor put a specifier in front as (bool) for example). I was
wondering that maybe there is a templetized way to do this. For
example,
template<typename T>
....
typedef std::map<string,TMap;
but I don''t think it may work.....
aaragon写道：
aaragon wrote:
Thomas Tutone写道：
Thomas Tutone wrote:
aaragon写道：
aaragon wrote:
我想知道是否有办法使用std :: map存储
其中一个的不同类型类型。也就是说，我正在尝试使用
它：
>
typedef std :: map< string，doubleMap;
>
而不是双倍，我有整数，甚至是布尔值，所以我猜这个使用双倍浪费了大量的存储空间。有没有办法做到这一点？
也许有一个打字机？
I would like to know if there is a way to use the std::map to store
different types for one of its two types. That is, I''m trying to use
it as:
>
typedef std::map<string,doubleMap;
>
but instead of double, I have integers, even booleans so I guess that
the use of double waste a lot of storage. Is there any way to do this?
Maybe with a typename?
看一下boost :: any。如果这没有帮助，你可能需要更多地描述你想要做的事情。顺便说一下，虽然我可以看到没有使用双打的充分理由，但为什么你要关心浪费
存储？地图真的那么大吗？
祝你好运，
Tom
Take a look at boost::any. If that''s no help, you may need to describe
a bit more what it is you are trying to do. By the way, although I can
see good reasons not to use doubles, why do you care about wasting
storage? Is the map really that big?
Best regards,
Tom
$ b $嗯，不是地图很大，而且当你请求密钥时，
然后返回值。因此，有时候我会期待一个bool
但是我得到了一个双倍（我不想转换
值也不想放一个前面的说明符为（bool）例如）。我是b / b
想知道可能有一种神圣化的方式来做到这一点。对于
示例，
模板< typename T>
...
typedef std： ：map< string，TMap;
但我认为它不会起作用.....
Well, it''s not that the map is big, but also when you request the key,
then the value is returned. Therefore, sometimes I''m expecting a bool
but instead I''m receiving a double (and I don''t want to convert the
values nor put a specifier in front as (bool) for example). I was
wondering that maybe there is a templetized way to do this. For
example,
template<typename T>
...
typedef std::map<string,TMap;
but I don''t think it may work.....
不，那绝对不行。 C ++是一种强类型语言，你需要使用特定类型来实例化地图。正如我所说，
看看boost :: any（参见 www.boost .ORG）。或者你也可以这样做：/ b $ b类似以下内容：
struct Aaragon_multi_type {
int i;
double d;
bool b;
};
std :: map< std :: string，Aaragon_multi_type地图;
空间效率不高，但会在
地图中存储任何值的商品......
再次，如果你不告诉我们你想做什么 - 也就是说，为什么你想要存储不同类型的
？ - 提供
有用的建议非常困难。
祝你好运，
汤姆
No, that definitely won''t work. C++ is a strongly typed language, and
you need to instantiate the map using a particular type. As I said,
look at boost::any (see www.boost.org). Or maybe you can just do
something like the following:
struct Aaragon_multi_type {
int i;
double d;
bool b;
};
std::map<std::string, Aaragon_multi_type map;
Not space efficient, but would let store value of any of those in the
map...
Again, if you don''t tell us what it is you want to do - i.e., why do
you want to store different types? - it''s awfully hard to provide
useful advice.
Best regards,
Tom
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