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with_rounding

with_rounding(f::Function, T, mode)

Change the rounding mode of floating point type T for the duration of f. It is logically equivalent to:

old = get_rounding(T)
set_rounding(T, mode)
f()
set_rounding(T, old)

See get_rounding for available rounding modes.

Examples

In the Julia programming language, the with_rounding function allows you to change the rounding mode of a floating point type T for the duration of a given function f. It follows the logical steps:

1. Save the current rounding mode of type T using get_rounding(T).
2. Set the rounding mode of type T to the desired mode using set_rounding(T, mode).
3. Execute the function f().
4. Restore the original rounding mode of type T using set_rounding(T, old).

Here are some examples of how to use the with_rounding function:

1. Round a floating-point operation with different rounding modes:

   julia> x = 1.5;
   julia> with_rounding(RoundDown, Float64) do
             x = x / 2
         end
   0.75

   In this example, the value of x is divided by 2 using the RoundDown rounding mode.

2. Calculate the square root with increased precision:

   julia> precision = BigFloat.precision;
   julia> with_rounding(RoundUp, BigFloat) do
             sqrt(BigFloat(2))
         end
   1.414213562373095048801688724209698078569671875376948073176679737990732478462107038850387534327641573

   This example calculates the square root of 2 with increased precision using the RoundUp rounding mode.

3. Perform a custom rounding operation:

   julia> with_rounding(RoundNearest, Float64) do
             round(Int, 3.7)
         end
   4

   Here, the round function is called within the with_rounding context to perform rounding to the nearest integer.

Remember that get_rounding provides available rounding modes for a specific floating point type.

See Also

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