[boost] lexical_cast again...

From: Stéphane Bronsart (stephane.bronsart_at_[hidden])
Date: 2002-07-03 02:47:13

Hi,

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A signed long can hold value from -2147483648 to 2147483647

signed long l;

1) l=lexical_cast<signed long>("2147483647");      // Ok l = 2147483647
2) l=lexical_cast<signed long>("2147483648");      // False : no exception
and l = -2147483648
3) l=lexical_cast<signed long>("2147483650");      // OK exception occurs
!!!

Why case 2 don't throw exception and case 3 yes ?
If lexical_cast throw exption with a value 3 unit greater than the limit,
why not with a value 1 greater than the limit ?

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User had to know that :
signed short i = 60000;
produce a fault value in i.
This behavior is in the C/C++ documentation
Thus I'm agree with you that lexical_cast had to clearly explain WHAT it can
do...

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My modified lexical_cast is not optimized you said.
I'm agree with you, but generaly I prefer a non-optimized solution which
work (I don't talk about lexical_cast here ) without ambiguity again an
optimized solution with "limit" case and/or undefined result in some (rare)
situation.

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Don't you think it's time now to :
1) Review lexical_cast implementation and/or documentation : You are the
best guy to do that.
And/Or
2) Provide via boost a "specialized" lexical_cast like feature to perform
well "numeric to string" ONLY and vice/versa convertion.

I'm new in the C/C++ worls, but i seems me crazy that a so used operation is
not yet fixed in the language (or in a "standard" library).  All the
programmers around the world had to perform string/integer conversion.  It
must be possible to perform this task without using a strstream (heavy).
The final solution, for me, is a "specialized" conversion routine/template
dedicated to string/integer conversion.

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Regards.
Steph.