Tango error : cannot modify immutable expression *p++

[jeromeG]

Hi people,

I am using the tango-1.0.5_2.0.85 package in my project, for some 
reasons :)

This packages contains tango/tango/text/convert/Float.d

I was just compiling my program and got this error:

../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(251,13): Error: cannot modify immutable expression *p++

In fact, there are a dozen similar errors with Float.d, because 
the code shows the following in different places:

-----
         auto p = dst.ptr;
         if (sign)
             *p++ = '-'; <<< this is problematic
-----

dst is from the function argument list :

T[] format(T) (T[] dst, NumType x, int decimals=Dec, int e=Exp, 
bool pad=Pad)


I don't understand why dst is immutable at the first place... I 
guess the error pops up because the template argument passed as T 
is immutable itself. But in this case, I don't see how we can 
return a modified dst at any point.
I try a few Rebindable combos, but a bit randomly, as I don't 
understand exactly what Rebindable is for. Not to avail.

Compiler output:
-------------------------
$ dub build
Performing "debug" build using 
/home/jegau/dlang/dmd-2.093.1/linux/bin64/dmd for x86_64.
diamond ~master: building configuration "library"...
src/diamond/core/misc.d(177,27): Error: undefined identifier 
doFormat in module std.format
src/diamond/gui/surfacegeometry.d(163,13): Warning: ubyte *= 
float is performing truncating conversion
src/diamond/gui/surfacegeometry.d(174,7): Warning: ubyte *= float 
is performing truncating conversion
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(251,13): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(255,20): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(261,15): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(265,18): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/convert/Float.d(267,25): Error: cannot modify immutable expression *p++
.... (more similar errors)

Any shining light appreciated.