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Does printf("%x",1) invoke undefined behavior?

According to the C standard (6.5.2.2 paragraph 6) If the expression that denotes the called function has a type that does not include a[详细]

2023-02-03 13:37 分类：问答
The effect of `basic_streambuf::setbuf`

My problem is as follows: Martin York claims in this, this, and this answers that one can make a stringstream read from some piece of memory by using basic_stringbuf::pubsetbuf like this:[详细]

2023-01-28 01:50 分类：问答
Where exactly does C++ standard say dereferencing an uninitialized pointer is undefined behavior?

So far I can\'t find how to deduce that the following: int* ptr; *ptr = 0; is undefined behavior. First of all, there\'s 5.3.1/1 that states that * means indirection which converts T* to T. But th[详细]

2023-01-26 21:32 分类：问答
Type requirements for std::map

Today I created a map, where the value type has no default constructor. I was surprised that I could not use operator[] to insert the elements to this map, but I had to use the insert method.[详细]

2023-01-26 06:03 分类：问答
Defining a function with different signature

Today I discovered that it is possible to declare a function in a header with one signature, and implement it in the source file with different (similar) signature. For example, like this :[详细]

2023-01-26 04:53 分类：问答
A virtual member function is used if it is not pure?

C++03 3.2.2 ...An object or non-overloaded function is used if its name appears in a potentially-evaluated expression. A virtual member function is used if it is not pure...[详细]

2023-01-24 15:18 分类：问答
Is a main() required for a C program?

Well the title says it all. Is a main() function absolutely essential for a C program? I am asking开发者_如何转开发 this because I was looking at the Linux kernel code, and I didn\'t see a main() fun[详细]

2023-01-23 15:22 分类：问答
anonymous empty untagged classes, structs, unions, and enums

!Disclaimer!: Please note that I am talking about untagged declarations. I know it\'s a possibly informal term and what I mean by it is that the declaration is not a typedef and it does not declare an[详细]

2023-01-23 11:18 分类：问答
Representation of negative numbers in C?

How does C represent negative integers? Is it by two\'s complement representation or by using the MSB (most significant bit)?[详细]

2023-01-20 02:34 分类：问答
Unsequenced value computations (a.k.a sequence points)

Sorry for opening this topic again, but thinking about this topic itself has started giving me an Undefined Behavior. Want to move into the zone of well-defined behavior.[详细]

2023-01-19 01:41 分类：问答