在我挠了头3个多小时后,我终于放弃了,决定请你们帮忙.
我有一些文件,它们将编译成一个可执行文件.
随着-stdlib=libc++ flag,我会得到
/usr/include/c++/v1/string:1938:44: error: 'basic_string<_CharT, _Traits, _Allocator>' is missing exception specification 'noexcept(is_nothrow_copy_constructible<allocator_type>::value)'
basic_string<_CharT, _Traits, _Allocator>::basic_string(const allocator_type& __a)
^
/usr/include/c++/v1/string:1326:40: note: previous declaration is here
_LIBCPP_INLINE_VISIBILITY explicit basic_string(const allocator_type& __a)
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我做了一些搜索,而另一个问题则是疑问.更改为 -stdlib=libstdc++,我在控制台中获得了大量输出.
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:382: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:382: undefined reference to `std::allocator<char>::~allocator()'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:382: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:382: undefined reference to `std::allocator<char>::~allocator()'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:399: undefined reference to `std::allocator<char>::allocator()'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:399: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/home/bobby/Documents/freshmen/225/cs225/lab_intro/png.cpp:399: undefined …Run Code Online (Sandbox Code Playgroud) 我在线阅读JavaScript文档,您可以捕获从createUserWithEmailAndPassword函数返回的错误代码,以确定它是否已经使用过电子邮件,密码太弱等等.我如何在Java中执行此操作?
这在JavaScript中可以告诉它是什么错误.
firebase.auth().signInWithEmailAndPassword(email, password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// ...
});
Run Code Online (Sandbox Code Playgroud) 我在主要活动中登录用户,但我想通过按钮注销另一个活动中的用户.但是,我无法将FirebaseAuth对象传递给其他活动.
PutParcelable和PutSerializable不起作用,因为我无法控制类本身.共享首选项仅接受原始类型.我是否应该在新活动中获得新实例并在新活动中注销用户?即使我得到一个新实例,用户的状态是否会被保留?
这是代码
mAuth = FirebaseAuth.getInstance();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
// User is signed in
Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());
Toast.makeText(getApplicationContext(), "You are logged in!!!",
Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, CameraActivity.class);
startActivity(intent);
} else {
// User is signed out
Log.d(TAG, "onAuthStateChanged:signed_out");
}
}
};
Run Code Online (Sandbox Code Playgroud) 我有一个字符串
"aaabbbbccc"
我想找回
["aaa", "bbbb", "ccc"]
根据这篇文章 什么正则表达式可以匹配相同字符的序列?
In [8]: re.findall('(\w)\1+', s)
Out[8]: []
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我想我使用在线正则表达式解析器成功检索到了这个模式。
在一个非常简单的C++程序中,我一直在研究这个内存泄漏问题.我正确地删除了唯一的指针分配但仍然发生了大量的内存泄漏.我的课程都没有变数.
所有方法只打印一个sinple硬编码字符串
主要
#include <iostream>
#include "queen.h"
#include "piece.h"
using namespace std;
void printPiece(piece *p) {
cout<<"In printPiece, printType() of the same memory address is:"<<endl;
p->printType();
}
int main() {
queen *q = new queen();
cout<<"In main, printType() of queen *q is:"<<endl;
q->printType();
printPiece(q);
delete q;
return 0;
}
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片类
#ifndef _PIECE_H
#define _PIECE_H
class piece {
public:
void printType();
};
#endif
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女王
#ifndef _QUEEN_H
#define _QUEEN_H
#include "piece.h"
class queen : public piece{
public:
void printType();
};
#endif
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Valgrind在MacOS上 …