(02/16/2007更新)compiler會給我們no appropriate default constructor available的錯誤訊息,也就是說,不寫其他constructor則已,一旦寫了其他的constructor,compiler就不會幫我們產生synthesized default constructor,若我們有用到default constructor
回答：改两处,基类的构造函数没有默认的,要么加上默认的,要么显式调用带参版本的基类构造。
1.http://stackoverflow.com/questions/24182687/c-newbie-error-c2512-no-appropriate-default-constructor-available
derive::derive(float i) : base(i){cout<<i<<endl;} 就行了 错误原因：base没有默认的无参构造函数，所以派生类在构造的时候，不知道怎么构造基类
private: A myA; }; B::B() : myA (42) // 'myA' must be initialized here because A has no default constructor { } Tuesday, December 16, 2008 3:11 PM Top explanation! This error is quite subtle for me... :) Thank you!
What if the designer provides multiple constructors but no default constructor? The compiler augments each constructor with the code necessary to invoke all required default constructors. However, it does not synthesize a default constructor because of the presence of the other user-supplied constructor...
有无异常移动构造函数 (has_nothrow_move_constructor) is_nothrow_move_constructible(是否无异常移动构造) no异常分配 is_nothrow_copy_assignable(是否不抛异常的可拷贝赋值) 无异常副本分配 is_nothrow_copy_assignable(是否不抛异常的可拷贝赋值) 确保无异常移动赋值 is_nothrow_move_assignable 具有普通构造函数 is...
vs2010运行QT5 error C2512: 'Ui::xxxxxx' : no appropriate default constructor available,程序员大本营,技术文章内容聚合第一站。
default: printf("%c",c); } } return 0; } Splint's 输出 Variable c used before definition Suspected infinite loop. No value used in loop test (c) is modified by test or loop body. Assignment of int to char: c = getchar()
This is known as "the rule of five" or "the rule of six", depending on whether you count the default constructor. 这就是众所周知的"5特殊函数规则"或者"6特殊函数规则",不同之处在于是否将默认构造函数算进来。 Note(注意) If you want a default implementation of a default operation (while de...