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Questions tagged [size-t]

In C and C++, size_t is the unsigned integer type of the result of the sizeof operator

size_t can store the maximum size of a theoretically possible object of any type (including array).

When indexing C++ containers, such as std::string, std::vector... the appropriate type is the member typedef size_type provided by such containers (it's usually defined as a synonym for size_t).

Further details:

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What is size_t in C?

I am getting confused with size_t in C. I know that it is returned by the sizeof operator. But what exactly is it? Is it a data type? Let's say I have a for loop: for(i = 0; i < some_size; i++) Should I use int i; or size_t i;?
Vijay
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unsigned int vs. size_t

I notice that modern C and C++ code seems to use size_t instead of int/unsigned int pretty much everywhere - from parameters for C string functions to the STL. I am curious as to the reason for this and the benefits it brings.
Rob
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size_t vs. uintptr_t

The C standard guarantees that size_t is a type that can hold any array index. This means that, logically, size_t should be able to hold any pointer type. I've read on some sites that I found on the Googles that this is legal and/or should always…
Chris Lutz
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When to use std::size_t?

I'm just wondering should I use std::size_t for loops and stuff instead of int? For instance: #include int main() { for (std::size_t i = 0; i < 10; ++i) { // std::size_t OK here? Or should I use, say, unsigned int instead? …
nhaa123
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Difference between size_t and std::size_t

What are the differences between size_t and std::size_t in terms of where they are declared, when they should be used and any other differentiating features?
Mankarse
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Should I use size_t or ssize_t?

At my code, I do not use int or unsigned int. I only use size_t or ssize_t for portable. For example: typedef size_t intc; // (instead of unsigned int) typedef ssize_t uintc; // (instead of int) Because strlen, string, vector... all use…
hgyxbll
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Clean code to printf size_t in C++ (or: Nearest equivalent of C99's %z in C++)

I have some C++ code that prints a size_t: size_t a; printf("%lu", a); I'd like this to compile without warnings on both 32- and 64-bit architectures. If this were C99, I could use printf("%z", a);. But AFAICT %z doesn't exist in any standard C++…
Justin L.
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Platform independent size_t Format specifiers in c?

I want to print out a variable of type size_t in C but it appears that size_t is aliased to different variable types on different architectures. For example, on one machine (64-bit) the following code does not throw any warnings: size_t size =…
Ethan Heilman
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What is a portable method to find the maximum value of size_t?

I'd like to know the maximum value of size_t on the system my program is running. My first instinct was to use negative 1, like so: size_t max_size = (size_t)-1; But I'm guessing there's a better way, or a constant defined somewhere.
Justicle
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How to cast the size_t to double or int C++

My question is that I have a size_t data, but now I want to convert it to double or int. If I do something like size_t data = 99999999; int convertdata = data; the compiler will report warning. because it maybe overflow. Do you have some method…
user2701639
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Why is size_t unsigned?

Bjarne Stroustrup wrote in The C++ Programming Language: The unsigned integer types are ideal for uses that treat storage as a bit array. Using an unsigned instead of an int to gain one more bit to represent positive integers is almost never a good…
Jon
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Does "std::size_t" make sense in C++?

In some code I've inherited, I see frequent use of size_t with the std namespace qualifier. For example: std::size_t n = sizeof( long ); It compiles and runs fine, of course. But it seems like bad practice to me (perhaps carried over from…
jwfearn
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What's sizeof(size_t) on 32-bit vs the various 64-bit data models?

On a 64-bit system, sizeof(unsigned long) depends on the data model implemented by the system, for example, it is 4 bytes on LLP64 (Windows), 8 bytes on LP64 (Linux, etc.). What's sizeof(size_t) supposed to be? Does it vary with data model like…
anonymous
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What is the return type of sizeof operator?

What is the return type of sizeof operator? cppreference.com & msdn says sizeof returns size_t. Does it really return a size_t? I'm using VS2010 Professional, and targeting for x64. int main() { int size = sizeof(int); // No warning …
Coder777
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Why is the maximum size of an array "too large"?

I'm under the same impression as this answer, that size_t is always guaranteed by the standard to be large enough to hold the largest possible type of a given system. However, this code fails to compile on gcc/Mingw: #include #include…
Lundin
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