C++ boost::make_shared 现在过时了吗？
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Is boost::make_shared obsolete now?
提问by Steve
Is boost::make_sharedobsolete now? Haven't found its definition in 1.35.
现在boost::make_shared过时了吗？在 1.35 中没有找到它的定义。
采纳答案by Ryan Cook
Its in the 1.4 docs: http://www.boost.org/doc/libs/1_40_0/libs/smart_ptr/make_shared.html
它在 1.4 文档中：http: //www.boost.org/doc/libs/1_40_0/libs/smart_ptr/make_shared.html
It appears to have been added in version 1.39
它似乎已在 1.39 版中添加
回答by nosid
std::make_sharedis also available in C++11. Please note that make_sharedis more than just a convenience function. Take a look at the following code fragment:
std::make_shared在 C++11 中也可用。请注意，这make_shared不仅仅是一个方便的功能。看看下面的代码片段：
make_shared<foobar>(1, 2);
shared_ptr<foobar>(new foobar(1, 2));
Both statements create a foobarobject and construct a shared_ptr. However, the former avoids a memory allocation for the shared counter, because a single memory chunk will be used for the counter and the foobar object. This is not possible with the second statement, because the memory for foobaris allocated before the shared_ptris constructed.
这两个语句都创建了一个foobar对象并构造了一个shared_ptr. 然而，前者避免了为共享计数器分配内存，因为单个内存块将用于计数器和 foobar 对象。这在第二条语句中是不可能的，因为在构造foobar之前分配了内存shared_ptr。
What I want to say: No, make_sharedis not obsolete, because it provides a very useful optimization.
我想说的是：不，make_shared并没有过时，因为它提供了非常有用的优化。
回答by Alex Z
Did a bit of research today, and it seems that make_shared actually was added to 1.36.0 (in 1.35.0 there is no such header), but the interesting thing is that there is no single mention in What's new about this change - at least I could not find it
今天做了一些研究，似乎make_shared实际上是添加到1.36.0中的（在1.35.0中没有这样的标题），但有趣的是，在What's new about this change - at至少我找不到它
