所有权/删除区域设置中的方面（std::locale）
我编写了以下函数来使用 boost 获取日期/时间字符串。日期_时间。
namespace bpt = boost::posix_time;
string
get_date_time_string(bpt::ptime time)
{
bpt::time_facet * facet(new bpt::time_facet);
facet->format("%Y%m%d%H%M%S");
stringstream return_value;
return_value.imbue(std::locale(std::locale::classic(), facet));
return_value << time;
return return_value.str();
}
我有一个关于facet对象的所有权/删除的快速问题。 std::locale 的构造函数 在所有权上不明确/删除facet。尝试使用shared_ptr包装和堆栈分配版本的facet - 这两者都会导致段错误。另外，通过 valgrind 运行上述函数没有显示任何泄漏（这可能意味着语言环境或流正在处理删除），但我只是想清楚我正在做正确的事情在这里。谢谢。
I wrote the following function to get a date/time string using boost.date_time.
namespace bpt = boost::posix_time;
string
get_date_time_string(bpt::ptime time)
{
bpt::time_facet * facet(new bpt::time_facet);
facet->format("%Y%m%d%H%M%S");
stringstream return_value;
return_value.imbue(std::locale(std::locale::classic(), facet));
return_value << time;
return return_value.str();
}
I had a quick question about the ownership/delete'ing of the facet object. std::locale's constructor is not explicit on the ownership/delete'ing of the facet. Tried using shared_ptr-wrapped and stack allocated versions of facet - both of which caused seg-faults. Also, running the above function through valgrind didn't show any leaks(which probably implies that the locale or stream is taking care of delete'ing), but I just wanted to be clear that I am doing the right thing here. Thanks.
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根据 Stroustrup，传递给构造函数的 0 参数告诉
facetlocale将处理销毁，并且bpt::time_facet的两个构造函数在未提供时默认为 0。不过，非零值意味着程序员必须显式处理facet的销毁。According to Stroustrup, a 0 argument passed to the constructor tells the
facetthat thelocalewill handle destruction, and the both constructors ofbpt::time_facetdefault to 0 when it isn't supplied. A non-zero value, though, implies that the programmer must explicitly handle the destruction of thefacet.