Ada Programming/Attributes/'Copy Sign

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Ada Lovelace 1838.jpg

function S'Copy_Sign (Value, Sign : T)
  return T

Description[edit]

S'Copy_Sign(X, Y) is an Ada attribute where S is any floating-point type, and X and Y are any instance of that type. This attribute represents the floating point value with the magnitude of X and the sign of Y.

If the resulting value is outside the range of S, a Constraint_Error exception is raised.

Example[edit]

X : Float :=  1.5;
Y : Float := -1.0;
Z : Float :=  1.0;
 
pragma Assert (Float'Copy_Sign ( X, Y) = -1.5);   -- OK
pragma Assert (Float'Copy_Sign ( X, Z) =  1.5);   -- OK
pragma Assert (Float'Copy_Sign (-X, Z) =  1.5);   -- OK
pragma Assert (Float'Copy_Sign ( Y, Z) = -1.0);   -- Wrong

See also[edit]

Wikibook[edit]

Ada Reference Manual[edit]