为什么 std::move 未定义，尽管编译器使用 -std=c++11 调用

Why is std::move undefined although compiler invoked with -std=c++11?

本文关键字：-std c++11 调用 编译器 move std 未定义 为什么      更新时间：2023-10-16

我想在OSX上编译kenlm，但我收到错误：

error: no member named 'move' in namespace 'std'

其他帖子建议编译

'

-std=c++11'

但我仍然遇到同样的错误。我该如何解决这个问题？

g++ --version输出：

Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.1.0 (clang-802.0.38)
Target: x86_64-apple-darwin16.5.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

kenlm 的构建脚本如下所示：

from setuptools import setup, Extension
import glob
import platform
import os
#Does gcc compile with this header and library?
def compile_test(header, library):
    dummy_path = os.path.join(os.path.dirname(__file__), "dummy")
    command = "bash -c "g++ -include " + header + " -l" + library + " -x c++ - <<<'int main() {}' -o " + dummy_path + " >/dev/null 2>/dev/null && rm " + dummy_path + " 2>/dev/null""
    return os.system(command) == 0
...
#We don't need -std=c++11 but python seems to be compiled with it now.  https://github.com/kpu/kenlm/issues/86
ARGS = ['-O3', '-DNDEBUG', '-DKENLM_MAX_ORDER=6', '-std=c++11']
ext_modules = [
    Extension(name='kenlm',
        sources=FILES + ['python/kenlm.cpp'],
        language='C++', 
        include_dirs=['.'],
        libraries=LIBS, 
        extra_compile_args=ARGS)
]
...

使用std::move的代码：

#ifndef UTIL_FILE_STREAM_H
#define UTIL_FILE_STREAM_H
#include <utility>
#include "util/fake_ostream.hh"
#include "util/file.hh"
#include "util/scoped.hh"
#include <cassert>
#include <cstring>
#include <stdint.h>
namespace util {
class FileStream : public FakeOStream<FileStream> {
  public:
    explicit FileStream(int out = -1, std::size_t buffer_size = 8192)
      : buf_(util::MallocOrThrow(std::max<std::size_t>(buffer_size, kToStringMaxBytes))),
        current_(static_cast<char*>(buf_.get())),
        end_(current_ + std::max<std::size_t>(buffer_size, kToStringMaxBytes)),
        fd_(out) {}
#if __cplusplus >= 201103L
    FileStream(FileStream &&from) noexcept : buf_(std::move(from.buf_)), current_(from.current_), end_(from.end_), fd_(from.fd_) {
      from.end_ = reinterpret_cast<char*>(from.buf_.get());
      from.current_ = from.end_;
    }
#endif

根据 GNU CC 标准库特性矩阵，std::move (N2812( §"对标准库的影响"仅在 4.5 版中添加，并在 4.6 版中修订。

您应该将标准库版本更新到版本 4.5(至少(。你的是 4.2.1。

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