# Int64.3o - Man Page

64-bit integers.

## Module

Module Int64

## Documentation

Module **Int64**

: **sig end**

64-bit integers.

This module provides operations on the type **int64** of signed 64-bit integers. Unlike the built-in **int** type, the type **int64** is guaranteed to be exactly 64-bit wide on all platforms. All arithmetic operations over **int64** are taken modulo 2^64

Performance notice: values of type **int64** occupy more memory space than values of type **int** , and arithmetic operations on **int64** are generally slower than those on **int** . Use **int64** only when the application requires exact 64-bit arithmetic.

Literals for 64-bit integers are suffixed by L:

let zero: int64 = 0L let one: int64 = 1L let m_one: int64 = -1L

*val zero* : **int64**

The 64-bit integer 0.

*val one* : **int64**

The 64-bit integer 1.

*val minus_one* : **int64**

The 64-bit integer -1.

*val neg* : **int64 -> int64**

Unary negation.

*val add* : **int64 -> int64 -> int64**

Addition.

*val sub* : **int64 -> int64 -> int64**

Subtraction.

*val mul* : **int64 -> int64 -> int64**

Multiplication.

*val div* : **int64 -> int64 -> int64**

Integer division.

**Raises Division_by_zero** if the second argument is zero. This division rounds the real quotient of its arguments towards zero, as specified for **(/)** .

*val unsigned_div* : **int64 -> int64 -> int64**

Same as **Int64.div** , except that arguments and result are interpreted as unsigned 64-bit integers.

**Since** 4.08.0

*val rem* : **int64 -> int64 -> int64**

Integer remainder. If **y** is not zero, the result of **Int64.rem x y** satisfies the following property: **x = Int64.add (Int64.mul (Int64.div x y) y) (Int64.rem x y)** . If **y = 0** , **Int64.rem x y** raises **Division_by_zero** .

*val unsigned_rem* : **int64 -> int64 -> int64**

Same as **Int64.rem** , except that arguments and result are interpreted as unsigned 64-bit integers.

**Since** 4.08.0

*val succ* : **int64 -> int64**

Successor. **Int64.succ x** is **Int64.add x Int64.one** .

*val pred* : **int64 -> int64**

Predecessor. **Int64.pred x** is **Int64.sub x Int64.one** .

*val abs* : **int64 -> int64**

Return the absolute value of its argument.

*val max_int* : **int64**

The greatest representable 64-bit integer, 2^63 - 1.

*val min_int* : **int64**

The smallest representable 64-bit integer, -2^63.

*val logand* : **int64 -> int64 -> int64**

Bitwise logical and.

*val logor* : **int64 -> int64 -> int64**

Bitwise logical or.

*val logxor* : **int64 -> int64 -> int64**

Bitwise logical exclusive or.

*val lognot* : **int64 -> int64**

Bitwise logical negation.

*val shift_left* : **int64 -> int -> int64**

**Int64.shift_left x y** shifts **x** to the left by **y** bits. The result is unspecified if **y < 0** or **y >= 64** .

*val shift_right* : **int64 -> int -> int64**

**Int64.shift_right x y** shifts **x** to the right by **y** bits. This is an arithmetic shift: the sign bit of **x** is replicated and inserted in the vacated bits. The result is unspecified if **y < 0** or **y >= 64** .

*val shift_right_logical* : **int64 -> int -> int64**

**Int64.shift_right_logical x y** shifts **x** to the right by **y** bits. This is a logical shift: zeroes are inserted in the vacated bits regardless of the sign of **x** . The result is unspecified if **y < 0** or **y >= 64** .

*val of_int* : **int -> int64**

Convert the given integer (type **int** ) to a 64-bit integer (type **int64** ).

*val to_int* : **int64 -> int**

Convert the given 64-bit integer (type **int64** ) to an integer (type **int** ). On 64-bit platforms, the 64-bit integer is taken modulo 2^63, i.e. the high-order bit is lost during the conversion. On 32-bit platforms, the 64-bit integer is taken modulo 2^31, i.e. the top 33 bits are lost during the conversion.

*val unsigned_to_int* : **int64 -> int option**

Same as **Int64.to_int** , but interprets the argument as an unsigned integer. Returns **None** if the unsigned value of the argument cannot fit into an **int** .

**Since** 4.08.0

*val of_float* : **float -> int64**

Convert the given floating-point number to a 64-bit integer, discarding the fractional part (truncate towards 0). The result of the conversion is undefined if, after truncation, the number is outside the range [ **Int64.min_int** , **Int64.max_int** ].

*val to_float* : **int64 -> float**

Convert the given 64-bit integer to a floating-point number.

*val of_int32* : **int32 -> int64**

Convert the given 32-bit integer (type **int32** ) to a 64-bit integer (type **int64** ).

*val to_int32* : **int64 -> int32**

Convert the given 64-bit integer (type **int64** ) to a 32-bit integer (type **int32** ). The 64-bit integer is taken modulo 2^32, i.e. the top 32 bits are lost during the conversion.

*val of_nativeint* : **nativeint -> int64**

Convert the given native integer (type **nativeint** ) to a 64-bit integer (type **int64** ).

*val to_nativeint* : **int64 -> nativeint**

Convert the given 64-bit integer (type **int64** ) to a native integer. On 32-bit platforms, the 64-bit integer is taken modulo 2^32. On 64-bit platforms, the conversion is exact.

*val of_string* : **string -> int64**

Convert the given string to a 64-bit integer. The string is read in decimal (by default, or if the string begins with **0u** ) or in hexadecimal, octal or binary if the string begins with **0x** , **0o** or **0b** respectively.

The **0u** prefix reads the input as an unsigned integer in the range **[0, 2*Int64.max_int+1]** . If the input exceeds **Int64.max_int** it is converted to the signed integer **Int64.min_int + input - Int64.max_int - 1** .

The **_** (underscore) character can appear anywhere in the string and is ignored.

**Raises Failure** if the given string is not a valid representation of an integer, or if the integer represented exceeds the range of integers representable in type **int64** .

*val of_string_opt* : **string -> int64 option**

Same as **of_string** , but return **None** instead of raising.

**Since** 4.05

*val to_string* : **int64 -> string**

Return the string representation of its argument, in decimal.

*val bits_of_float* : **float -> int64**

Return the internal representation of the given float according to the IEEE 754 floating-point 'double format' bit layout. Bit 63 of the result represents the sign of the float; bits 62 to 52 represent the (biased) exponent; bits 51 to 0 represent the mantissa.

*val float_of_bits* : **int64 -> float**

Return the floating-point number whose internal representation, according to the IEEE 754 floating-point 'double format' bit layout, is the given **int64** .

*type t* = **int64**

An alias for the type of 64-bit integers.

*val compare* : **t -> t -> int**

The comparison function for 64-bit integers, with the same specification as **compare** . Along with the type **t** , this function **compare** allows the module **Int64** to be passed as argument to the functors **Set.Make** and **Map.Make** .

*val unsigned_compare* : **t -> t -> int**

Same as **Int64.compare** , except that arguments are interpreted as unsigned 64-bit integers.

**Since** 4.08.0

*val equal* : **t -> t -> bool**

The equal function for int64s.

**Since** 4.03.0