错误：没有匹配函数调用‘std::__cxx11::basic_string<char>::basic_string(int&)’
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【中文标题】错误：没有匹配函数调用‘std::__cxx11::basic_string<char>::basic_string(int&)’【英文标题】：error: no matching function for call to ‘std::__cxx11::basic_string<char>::basic_string(int&)’ 【发布时间】：2020-07-14 16:18:59 【问题描述】：嗯，我有这个代码：
#include <iostream>
#include "Stack.h"
#include <string>
using namespace std;
int main(int argc, char* argv[])
Stack<string> p(100);
p.push("python");
p.push("haskell");
p.push("C++");
//p.desempilhar();
if(p.isEmpty())
cout << "Pilha vazia!\n";
else
cout << "Pilha NAO vazia!\n";
if(!p.isEmpty())
cout << "Topo: " << p.peek() << endl;
else
cout << "A pilha esta vazia!!\n";
return 0;
以及文件夹/home/matheus/Codes/C++/EstruturaDeDados中的这个.h代码：
#ifndef __STACK_H_
#define __STACK_H_
#include <iostream>
using namespace std;
/*
Declarando a criação de um template para classe Stack.
Stack aqui é um template, não uma classe propriamente dita.
Ao ser declarada da maneira correta se torna uma classe de fato.
*/
template <class T>
class Stack
private:
int top;
T* a;
int MAX;
public:
Stack(int MAX);
bool push(T x); //Adiciona um T a stack.
bool pop(); //Remove o T mais acima da stack.
T peek(); //Retorna o T mais acima da stack.
bool isEmpty();
;
//Declarando uso de um template. template <class T>
template <class T>
//"Stack<T>" é uma classe baseada no "template <class T>".
Stack<T>::Stack(int MAX)
a = new T(MAX);
top = -1;
this->MAX = MAX;
//Declarando uso de um template. template <class T>
template <class T>
//"Stack<T>" é uma classe baseada no "template <class T>".
bool Stack<T>::push(T x)
if (top >= (MAX - 1))
cout << "Stack Overflow" << endl;
return false;
else
a[++top] = x;
cout << x << " pushed into stack" << endl;
return true;
//Declarando uso de um template.
template <class T>
//"Stack<T>" é uma classe baseada no "template <class T>".
bool Stack<T>::pop()
if (top < 0)
cout << "Stack Underflow" << endl;
return false;
else
cout << a[top--] << " Popped from stack" << endl;
return true;
//Declarando uso de um template.
template <class T>
//"Stack<T>" é uma classe baseada no "template <class T>".
T Stack<T>::peek()
if (top < 0)
cout << "Stack is Empty" << endl;
return NULL;
else
return a[top];
//Declarando uso de um template.
template <class T>
//"Stack<T>" é uma <<classe baseada no "template <class T>".
bool Stack<T>::isEmpty()
return (top < 0);
#endif
当我尝试编译时，我收到这个错误，我什至无法理解它是什么：
In file included from 21Templates.cpp:2:
/home/matheus/Codes/C++/EstruturaDeDados/Stack.h: In instantiation of ‘Stack<T>::Stack(int) [with T = std::__cxx11::basic_string<char>]’:
21Templates.cpp:8:21: required from here
/home/matheus/Codes/C++/EstruturaDeDados/Stack.h:32:9: error: no matching function for call to ‘std::__cxx11::basic_string<char>::basic_string(int&)’
a = new T(MAX);
^~~~~~~~~~
In file included from /usr/include/c++/8/string:52,
from /usr/include/c++/8/bits/locale_classes.h:40,
from /usr/include/c++/8/bits/ios_base.h:41,
from /usr/include/c++/8/ios:42,
from /usr/include/c++/8/ostream:38,
from /usr/include/c++/8/iostream:39,
from 21Templates.cpp:1:
/usr/include/c++/8/bits/basic_string.h:614:9: note: candidate: ‘template<class _InputIterator, class> std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(_InputIterator, _InputIterator, const _Alloc&)’
basic_string(_InputIterator __beg, _InputIterator __end,
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:614:9: note: template argument deduction/substitution failed:
In file included from 21Templates.cpp:2:
/home/matheus/Codes/C++/EstruturaDeDados/Stack.h:32:9: note: candidate expects 3 arguments, 1 provided
a = new T(MAX);
^~~~~~~~~~
In file included from /usr/include/c++/8/string:52,
from /usr/include/c++/8/bits/locale_classes.h:40,
from /usr/include/c++/8/bits/ios_base.h:41,
from /usr/include/c++/8/ios:42,
from /usr/include/c++/8/ostream:38,
from /usr/include/c++/8/iostream:39,
from 21Templates.cpp:1:
/usr/include/c++/8/bits/basic_string.h:576:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(basic_string&& __str, const _Alloc& __a)
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:576:7: note: candidate expects 2 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:572:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(const basic_string& __str, const _Alloc& __a)
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:572:7: note: candidate expects 2 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:568:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::initializer_list<_Tp>, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(initializer_list<_CharT> __l, const _Alloc& __a = _Alloc())
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:568:7: note: no known conversion for argument 1 from ‘int’ to ‘std::initializer_list<char’
/usr/include/c++/8/bits/basic_string.h:541:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(basic_string&& __str) noexcept
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:541:7: note: no known conversion for argument 1 from ‘int’ to ‘std::__cxx11::basic_string<char>&&’
/usr/include/c++/8/bits/basic_string.h:529:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, _CharT, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned int]’
basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc())
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:529:7: note: candidate expects 3 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:514:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’ <near match>
basic_string(const _CharT* __s, const _Alloc& __a = _Alloc())
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:514:7: note: conversion of argument 1 would be ill-formed:
In file included from 21Templates.cpp:2:
/home/matheus/Codes/C++/EstruturaDeDados/Stack.h:32:9: error: invalid conversion from ‘int’ to ‘const char*’ [-fpermissive]
a = new T(MAX);
^~~~~~~~~~
In file included from /usr/include/c++/8/string:52,
from /usr/include/c++/8/bits/locale_classes.h:40,
from /usr/include/c++/8/bits/ios_base.h:41,
from /usr/include/c++/8/ios:42,
from /usr/include/c++/8/ostream:38,
from /usr/include/c++/8/iostream:39,
from 21Templates.cpp:1:
/usr/include/c++/8/bits/basic_string.h:499:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned int’
basic_string(const _CharT* __s, size_type __n,
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:499:7: note: candidate expects 3 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:481:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned int]’
basic_string(const basic_string& __str, size_type __pos,
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:481:7: note: candidate expects 4 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:465:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned int]’
basic_string(const basic_string& __str, size_type __pos,
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:465:7: note: candidate expects 3 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:450:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned int]’
basic_string(const basic_string& __str, size_type __pos,
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:450:7: note: candidate expects 3 arguments, 1 provided
/usr/include/c++/8/bits/basic_string.h:437:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(const basic_string& __str)
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:437:7: note: no known conversion for argument 1 from ‘int’ to ‘const std::__cxx11::basic_string<char>&’
/usr/include/c++/8/bits/basic_string.h:429:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string(const _Alloc& __a) _GLIBCXX_NOEXCEPT
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:429:7: note: no known conversion for argument 1 from ‘int’ to ‘const std::allocator<char>’
/usr/include/c++/8/bits/basic_string.h:420:7: note: candidate: ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
basic_string()
^~~~~~~~~~~~
/usr/include/c++/8/bits/basic_string.h:420:7: note: candidate expects 0 arguments, 1 provided
.h 是堆栈的模板，我试图用以下代码编写所有这些：g++ -I /home/matheus/Codes/C++/EstruturaDeDados/ -o 21Templates 21Templates.cpp，但我一遍又一遍地接收这个错误。
我如何解决这个问题？那究竟是什么错误？
【问题讨论】：
好像你在Stack 的构造函数中使用参数 MAX 调用 T 的构造函数。您应该使用a = new T[MAX];（方括号，而不是括号）
是的，就是这样！！！
【参考方案1】：
此声明
a = new T(MAX);
尝试从整数值 MAX 创建 std::string 类型的对象。但是 std::string 类没有这样的构造函数。
看来你的意思
a = new T[MAX];
也就是说，您要创建一个 std::string 类型的对象数组。
这个函数
T Stack<T>::peek()
if (top < 0)
cout << "Stack is Empty" << endl;
return NULL;
else
return a[top];
也是错误的，因为从空指针创建 std::string 类型的对象会导致未定义的行为。您应该抛出异常，例如 std::out_of_range。
注意这个类没有析构函数。
您可以使用std::vector<std::string> 类来代替动态分配的数组。
【讨论】：
谢谢，您解释了错误和解决方法。我没有看到我使用的是 ( ) 而不是 [ ]。 我还没有研究 C++ 的异常，我在 java 上知道，我记得在这些情况下我返回 null，而我还不知道 java 异常。【参考方案2】：如果你想创建一个数组，改变这一行
a = new T(MAX);
到这里
a = new T[MAX];
记得稍后删除它，否则你会泄露内存
Stack::~Stack()
delete[] a;
【讨论】：
如果你提到析构函数，你也应该提到三的规则。内存泄漏不会导致 UB，缺少复制构造函数可能会。 @Yksisarvinen 什么是三规则？ @FUNKYBAT 看到这个问题：What is The Rule of Three?以上是关于错误：没有匹配函数调用‘std::__cxx11::basic_string<char>::basic_string(int&)’的主要内容，如果未能解决你的问题，请参考以下文章