User documentation for file utils.H
This file defines a few very basic functions which I feel should
really be part of the standard C++. Nevertheless I have placed all
definitions inside the namespace CoCoA
. Here is a summary:
round(x)
-- roundx
(of typedouble
) to nearest integer value (of typedouble
); halves round towards +infinity.ULongDiff(hi,lo)
-- computeshi-lo
as unsigned long (assumeshi>=lo
)LongRange(lo,hi)
-- returns avector<long>
filled withlo,lo+1,...,hi
(useful forsubmat
)IsDecimal(strm)
-- returnstrue
is i/o streamstrm
is in decimal mode, o/w returnsfalse
MaxSquarableInteger<T>()
-- returns largest integer whose square fits in typeT
fold(str, n)
-- make a copy of the stringstr
inserting a newline everyn
charslen(v)
-- same asv.size()
except that result islong
rather thansize_t
Maintainer documentation for files utils.H
Everything is in utils.H
;
the functions are all so simple that they can be implemented inline.
Impl of template fn MaxSquarableInteger
uses GMP to compute the
memorized values. A table of constants would be faster but potentially
less portable (given that CoCoALib requires GMP anyway). I haven't yet
found a neat way of ensuring that the type T
is integral & bounded.
Bugs, Shortcomings and other ideas
A possibly better idea for MaxSquarableInteger
: precompute 2^63*sqrt(2) as
unsigned long
, then simply right shift this value for integral types with
less than 127 bits. This suggestion presupposes a binary computer.
Main changes
2017
- February (v0.99543): added round; removed DeleteObject and cmp template fn.
- date of first release not noted