我正在开发一个 iOS 应用程序，并使用 Boost 库中的共享指针。我的应用程序有点笨重，所以我一直在努力精简它。我认为移动这一行：
#include <boost/shared_ptr.hpp>
从单个文件到预编译头文件将为我节省一些空间，因为我听说每次包含shared_ptr都会重新编译不同的版本，并且不清楚编译器是否正在删除重复项。
当我将此行移至 pch 文件时，我收到大量编译时错误，其中大部分是：
error: expected '=', ',', ';', 'asm' or '__attribute__' before 'boost'
我已将 .pch 文件更改为其信息中的 sourcecode.cpp.h 文件，但这还没有帮助了。
想法？
编辑：刚刚验证我的二进制文件中实际上存在已编译的shared_ptr的重复副本！
I'm developing an iOS app and am using the shared-pointer from the Boost library. My app is a little chunky, so I've been trying to lean it up. I think moving this line:
#include <boost/shared_ptr.hpp>
From individual files to the pre-compiled header file will save me some space since I heard every include of shared_ptr recompiles a different version and it's unclear whether the compiler is removing the duplicates.
When I move this line to the pch file I get a ton of compile-time errors, most of which are:
error: expected '=', ',', ';', 'asm' or '__attribute__' before 'boost'
I've changed the .pch file to be a sourcecode.cpp.h file in its info, but that hasn't helped.
Thoughts?
EDIT: Just verified that there are in fact duplicate copies of the compiled shared_ptr in my binary!
发布评论
评论（2）
您的项目中可能有 C 或 ObjC 源代码。
在这种情况下：
Xcode（默认情况下）会为项目中的每种语言/方言创建一个前缀，如果没有，仍然需要手动
#include。不幸的是，将标头移动到 pch 只能添加重复项。但是，它可以减少您的构建时间。You probably have C or ObjC sources in your project.
In that case:
Xcode (by default) creates a prefix for every language/dialect in your project, and if it doesn't, it's still manually
#included. Unfortunately, moving a header to a pch could only add duplicates. It could reduce your build times, however.您是否将 Boost 标头包含在 .m 文件或 .mm 文件中？因为在第一种情况下编译器将使用 Objective-C，在第二种情况下编译器将使用 Objective-C++。
Are you included Boost headers in a .m file or .mm files? Because in the first case the compiler will use Objective-C, in the second case Objective-C++.