STL中的container各有专长,最常用的是std::vector,可以完全取代array,第二常用的是std::list。std::vector的优点在于non-sequential access超快,新增数据于数据后端超快,但insert和erase任意资料则相当缓慢;std::list则是insert和erase速度超快,但non-sequential access超慢,此范例以实际时间比较vector和list间的优缺点。
std::vector deallocation causing access violation exception std::vector push_back memory corruption? stdafx not found stdafx.h(15) : fatal error C1083: Cannot open include file: 'afxwin.h': No such file or directory STDMETHODIMP Stop timer at any time and start it - MFC C++ string to wstr...
当然,类型保存也可以扩展到模板的使用,Clang保留了关于特定模板特殊化(如 std:::vector)在源代码中如何拼写的信息。比如说: $ clang -fsyntax-only t.cpp t.cpp:12:7: error: incompatible type assigning 'vector', expected 'std::string' (aka 'class std::basic_string') str = vec; ^ ~~~ 修复提...
下面是一个使用Gprof进行性能分析的简单示例: #include<iostream>#include<vector>voidfunc(){std::vector<int>v;for(inti=0;i<10000000;++i){v.push_back(i);}}intmain(){func();return0;} 我们可以通过以下命令进行编译和运行: g++ -pg -otesttest.cpp ./test gproftestgmon.out > analysis.txt 在...
Compiler warning (level 4) C4752found Intel(R) Advanced Vector Extensions; consider using/arch:AVX Compiler warning C4753Cannot find bounds for pointer; MPX intrinsic function ignored Compiler warning (level 4) C4754Conversion rules for arithmetic operations in the comparison at %s(%d) mean that ...
The iterator debugging feature has been taught to properly unwrap std::move_iterator. For example, std::copy(std::move_iterator<std::vector<int>::iterator>, std::move_iterator<std::vector<int>::iterator>, int*) can now engage the memcpy fast path....
GetOrDefault(Opt::BootClassPathLocations); CHECK_EQ(dex_filenames.size(), dex_locations.size()); } std::vector<std::unique_ptr<const DexFile>> boot_class_path; OpenDexFiles(dex_filenames, dex_locations, runtime_options.GetOrDefault(Opt::Image), &boot_class_path); instruction_...
为 std::vector 的变量启用这些定义会将两个库的调试运行时长提高到大约 1350 ms [6],因此在启用类似功能时,我们的替换代码运行速度会更快。 发布的性能整体来看也略有提高,这是因为对于我们代码中的许多数组而言,std::vector 的构造函数执行的默认初始化是多余的,因为我们无论如何都要填充数组。当然,使用 std...
The C++ standard has always forbidden containers of const elements (such as vector<const T> or set<const T>). Visual Studio 2013 and earlier accepted such containers. In the current version, such containers fail to compile. std::allocator::deallocate In Visual Studio 2013 and earlier, std::...
std::vectorand other Standard Library containers The standard library containers all follow the principle of RAII. They provide iterators for safe traversal of elements. And, they're highly optimized for performance and have been thoroughly tested for correctness. By using these containers, you elimin...