在下面的第一个代码片段中,我试图根据馈入 std::remove 函数的静态条件函数从成员函数内的 vector 中删除一个元素。然后我在第二个片段中看到了很多模板错误。你能告诉我我错过了什么吗?
片段 1(代码)
void removeVipAddress(std::string &uuid)
{
struct RemoveCond
{
static bool condition(const VipAddressEntity & o)
{
return o.getUUID() == uuid;
}
};
std::vector<VipAddressEntity>::iterator last =
std::remove(
mVipAddressList.begin(),
mVipAddressList.end(),
RemoveCond::condition);
mVipAddressList.erase(last, mVipAddressList.end());
}
片段 2(编译输出)
/usr/include/c++/4.7/bits/random.h:4845:5: note: template<class _IntType> bool std::operator==(const std::discrete_distribution<_IntType>&, const std::discrete_distribution<_IntType>&)
/usr/include/c++/4.7/bits/random.h:4845:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.7/algorithm:63:0,
from Entity.hpp:12:
/usr/include/c++/4.7/bits/stl_algo.h:174:4: note: ‘ECLBCP::VipAddressEntity’ is not derived from ‘const std::discrete_distribution<_IntType>’
In file included from /usr/include/c++/4.7/random:50:0,
from /usr/include/c++/4.7/bits/stl_algo.h:67,
from /usr/include/c++/4.7/algorithm:63,
from Entity.hpp:12:
/usr/include/c++/4.7/bits/random.h:4613:5: note: template<class _RealType> bool std::operator==(const std::extreme_value_distribution<_RealType>&, const std::extreme_value_distribution<_RealType>&)
/usr/include/c++/4.7/bits/random.h:4613:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.7/algorithm:63:0,
from Entity.hpp:12:
/usr/include/c++/4.7/bits/stl_algo.h:174:4: note: ‘ECLBCP::VipAddressEntity’ is not derived from ‘const std::extreme_value_distribution<_RealType>’
最佳答案
我猜你是在寻找 std::remove_if()
,而不是 std::remove()
。
std::remove_if()
接受谓词作为它的第三个参数,并删除满足该谓词的元素。
std::remove()
将一个值作为第三个参数,并删除等于该值的元素。
编辑
要完成这项工作,您还必须将 RemoveCond
定义转换为谓词对象,因为它需要状态。像这样:
void removeVipAddress(std::string &uuid)
{
struct RemoveCond : public std::unary_function<VipAddressEntity, bool>
{
std::string uuid;
RemoveCond(const std::string &uuid) : uuid(uuid) {}
bool operator() (const VipAddressEntity & o)
{
return o.getUUID() == uuid;
}
};
std::vector<VipAddressEntity>::iterator last =
std::remove(
mVipAddressList.begin(),
mVipAddressList.end(),
RemoveCond(uuid));
mVipAddressList.erase(last, mVipAddressList.end());
}
关于c++ - 从 std::vector 中移除一个项目,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15025083/