Table of Contents
What is a fast integer C++?
The fast type (int_fast#_t) gives you an integer that’s the fastest type with a width of at least # bits (where # = 8, 16, 32, or 64). For example, int_fast32_t will give you the fastest integer type that’s at least 32 bits.
What is a fast int?
int is a “most efficient type” in speed/size – but that is not specified by per the C spec. It must be 16 or more bits. int_fast16_t is most efficient type in speed with at least the range of a 16 bit int.
What is the range of integer data type in C?
Data Types in C
| Data Type | Memory (bytes) | Range |
|---|---|---|
| int | 4 | -2,147,483,648 to 2,147,483,647 |
| long int | 4 | -2,147,483,648 to 2,147,483,647 |
| unsigned long int | 4 | 0 to 4,294,967,295 |
| long long int | 8 | -(2^63) to (2^63)-1 |
What are fast types C++?
The uint_fast*_t type simply defines the fastest type for representing a given number of bits. Think about it this way: you define a variable of type short and use it several times in the program, which is totally valid. However, the system you’re working on might work more quickly with values of type int .
What is the difference between int and int32_t?
Between int32 and int32_t , (and likewise between int8 and int8_t ) the difference is pretty simple: the C standard defines int8_t and int32_t , but does not define anything named int8 or int32 — the latter (if they exist at all) is probably from some other header or library (most likely predates the addition of …
How do I convert a number to a string in C++?
How to convert an int to a string in C++
- Using the stringstream class. The stringstream class is used to perform input/output operations on string-based streams.
- Using the to_string() method. The to_string() method accepts a value of any basic data type and converts it into a string.
- Using boost::lexical_cast.
What is a size T?
The datatype size_t is unsigned integral type. It represents the size of any object in bytes and returned by sizeof operator. It is used for array indexing and counting. It can never be negative. The return type of strcspn, strlen functions is size_t.
How long is integer data type?
The INTEGER data type stores whole numbers that range from -2,147,483,647 to 2,147,483,647 for 9 or 10 digits of precision. The number 2,147,483,648 is a reserved value and cannot be used. The INTEGER value is stored as a signed binary integer and is typically used to store counts, quantities, and so on.
What is long long int in C++?
long long int data type in C++ is used to store 64-bit integers. Being a signed data type, it can store positive values as well as negative values. Takes a size of 64 bits where 1 bit is used to store the sign of the integer.
What is the fastest integer type in C++?
To help address the above downsides, C++ also defines two alternative sets of integers. The fast type (std::int_fast#_t) provides the fastest signed integer type with a width of at least # bits (where # = 8, 16, 32, or 64). For example, std::int_fast32_t will give you the fastest signed integer type that’s at least 32 bits.
Why are fast types faster than normal types?
The fast types are not faster than all other integer types — they are in fact identical to some “normal” integer type (they’re just an alias for that type) — whichever type happens to be the fastest for holding a value of at least that many bits. It just platform-dependent which integer type each fast type is an alias for.
What is the best way to improve integer performance?
Ignore the “fast” types. If you are really concerned about integer performance, benchmark your code with all the available sizes.
Is 32 bit integer slower than 64 bit integer?
Second, if you use a fixed-width integer, it may be slower than a wider type on some architectures. For example, if you need an integer that is guaranteed to be 32-bits, you might decide to use std::int32_t, but your CPU might actually be faster at processing 64-bit integers.