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Tcl_DoubleObj(3)            Tcl Library Procedures            Tcl_DoubleObj(3)

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NAME

       Tcl_NewDoubleObj, Tcl_SetDoubleObj, Tcl_GetDoubleFromObj - manipulate
       Tcl values as floating-point values


SYNOPSIS

       #include <tcl.h>

       Tcl_Obj *
       Tcl_NewDoubleObj(doubleValue)

       Tcl_SetDoubleObj(objPtr, doubleValue)

       int
       Tcl_GetDoubleFromObj(interp, objPtr, doublePtr)


ARGUMENTS

       double doubleValue (in)              A double-precision floating-point
                                            value used to initialize or set a
                                            Tcl value.

       Tcl_Obj *objPtr (in/out)             For Tcl_SetDoubleObj, this points
                                            to the value in which to store a
                                            double value.  For
                                            Tcl_GetDoubleFromObj, this refers
                                            to the value from which to
                                            retrieve a double value.

       Tcl_Interp *interp (in/out)          When non-NULL, an error message is
                                            left here when double value
                                            retrieval fails.

       double *doublePtr (out)              Points to place to store the
                                            double value obtained from objPtr.
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DESCRIPTION

       These procedures are used to create, modify, and read Tcl values that
       hold double-precision floating-point values.

       Tcl_NewDoubleObj creates and returns a new Tcl value initialized to the
       double value doubleValue.  The returned Tcl value is unshared.

       Tcl_SetDoubleObj sets the value of an existing Tcl value pointed to by
       objPtr to the double value doubleValue.  The objPtr argument must point
       to an unshared Tcl value.  Any attempt to set the value of a shared Tcl
       value violates Tcl's copy-on-write policy.  Any existing string
       representation or internal representation in the unshared Tcl value
       will be freed as a consequence of setting the new value.

       Tcl_GetDoubleFromObj attempts to retrieve a double value from the Tcl
       value objPtr.  If the attempt succeeds, then TCL_OK is returned, and
       the double value is written to the storage pointed to by doublePtr.  If
       the attempt fails, then TCL_ERROR is returned, and if interp is non-
       NULL, an error message is left in interp.  The Tcl_ObjType of objPtr
       may be changed to make subsequent calls to Tcl_GetDoubleFromObj more
       efficient.


SEE ALSO

       Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult


KEYWORDS

       double, double value, double type, internal representation, value,
       value type, string representation

Tcl                                   8.0                     Tcl_DoubleObj(3)

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