Question

尝试编译下面包含的程序，我收到以下错误。在程序中应该修改什么才能成功编译？看起来像GCC 4.9.2不能实现一些noexcept移动构造函数为＆＃34; = default＆＃34;。

引起麻烦的一条线是： AssetLinkData::AssetLinkData(AssetLinkData&& other) noexcept = default;

编译错误：失败：obj / browser / asset_link_data.o g ++ -MMD -MF（我删除了更多标记）

asset_link_data.cc：错误：功能   ＆＃39; password_manager :: AssetLinkData :: AssetLinkData（password_manager :: AssetLinkData＆安培;＆安培;）＆＃39;   通过例外规范违反其重新声明   与隐含声明不同   ＆＃39; password_manager :: AssetLinkData :: AssetLinkData（password_manager :: AssetLinkData＆安培;＆安培;）＆＃39;   AssetLinkData :: AssetLinkData（AssetLinkData＆amp;＆amp; other）noexcept =   默认值;

消息代码：

#include "asset_link_data.h"

#include <algorithm>

#include <utility>

#include "base/json/json_reader.h"

#include "base/json/json_value_converter.h"

#include "base/values.h"

namespace password_manager { namespace {

constexpr char kGetLoginsRelation[] =
    "delegate_permission/common.get_login_creds"; constexpr char kWebNamespace[] = "web";

}  // namespace

AssetLinkData::AssetLinkData() = default;

AssetLinkData::AssetLinkData(AssetLinkData&& other) noexcept = default;

AssetLinkData::~AssetLinkData() = default; AssetLinkData& AssetLinkData::operator=(AssetLinkData&& other) = default;  
}  // namespace password_manager

下面我添加了asset_link_data.h的内容：

#ifndef COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_ASSET_LINK_DATA_H_
#define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_ASSET_LINK_DATA_H_

#include <string>
#include <vector>

#include "base/macros.h"
#include "url/gurl.h"

namespace password_manager {

// The class parses an asset link file. The spec for the format is
// https://github.com/google/digitalassetlinks/blob/master/well-known/details.md
// The class cares only about two types of statements:
// - includes. Those are just a reference to a file to be loaded and parsed.
// - "get_login_creds" permission to a web page. That means that the target is
//   allowed to get the credentials saved for the source.
// Only HTTPS URLs are taken into account.
class AssetLinkData {
 public:
  AssetLinkData();
  AssetLinkData(AssetLinkData&& other) noexcept;
  ~AssetLinkData();

  AssetLinkData& operator=(AssetLinkData&& other);

  bool Parse(const std::string& data);

  const std::vector<GURL>& includes() const { return includes_; }
  const std::vector<GURL>& targets() const { return targets_; }

 private:
  std::vector<GURL> includes_;
  std::vector<GURL> targets_;

  DISALLOW_COPY_AND_ASSIGN(AssetLinkData);
};

}  // namespace password_manager
#endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_ASSET_LINK_DATA_H_

Answer 1

错误信息非常清楚：

使用与隐式声明
不同的异常规范对其重新声明进行了默认

你已经要求编译器继续按照它的方式定义构造函数，但是还要求构造函数为noexcept ...并且默认创建的构造函数不是noexcept

要解决此问题，您需要删除noexcept说明符：

AssetLinkData::AssetLinkData(AssetLinkData&& other) = default;

或者，如果你想要一个no-except说明符，你需要用传统方式手工制作它：

AssetLinkData::AssetLinkData(AssetLinkData&& other) noexcept
: includes_(std::move(other.includes_))
, targets_ (std::move(other.targets_ ))
{}

gcc 4.9.2编译错误：AssetLinkData

1 个答案: