[expr] "raise to power" operator, similar to [pow] function

Returns an integer value if both arguments are integers, and [double]-precision floating-point otherwise.

The left operand may be any integer from Tcl's unlimited integer range.

The right operand is limited to a max integer value of 268435455 (0xfffffff) (28 bits).  (Unless the left operand is -1, 0, or 1, so that the answer is trivial).

Expect to wait a long while for [[expr 2**0xfffffff]] to return.
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**Precedence**
During early 2009, a thread broke out in the comp.lang.tcl usenet group discussing the observation that Tcl's calculation for 

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puts [expr {-2**2}]
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surprised someone who was expecting that to mean

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puts [expr {-(2**2)}
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while Tcl's operator precedence rules cause it to mean

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puts [expr {(-2)**2}
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[ZB] That "someone" must be a lawyer ;) Current TCL's way of calculation seems logical to me. If one's writing "second power of minus two", it means - logically - that the intention is "to raise minus two to power of two", and not: "raise two to two - then change sign". Interpreting the minus - if it's a very first sign of expression (when no parentheses) - as sign of the first operand (and not as changing the sign of final result) is just logical.
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!!!!!!
%| [Category Operator] | [Category Command] | [Category Mathematics] |%
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