• jeromeG (41/41) Sep 10 2020 Hi people,
• Paul Backus (3/16) Sep 10 2020 I haven't used Tango, but my guess is it's because strings are
• Jacob Carlborg (5/7) Sep 11 2020 Tango is compatible with D2. The version of Tango includes the last
• Jacob Carlborg (6/37) Sep 11 2020 I'm guessing `T` should to be `char`. There are some examples at the

jeromeG <jero.gaultier gmail.com> writes:

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/conv
rt/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/conv
rt/Float.d(251,13): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/conv
rt/Float.d(255,20): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/conv
rt/Float.d(261,15): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/conv
rt/Float.d(265,18): Error: cannot modify immutable expression *p++
../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/conv
rt/Float.d(267,25): Error: cannot modify immutable expression *p++
.... (more similar errors)

Any shining light appreciated.

Paul Backus <snarwin gmail.com> writes:

On Thursday, 10 September 2020 at 20:55:17 UTC, jeromeG wrote:
 I was just compiling my program and got this error:

 ../../../.dub/packages/tango-1.0.5_2.0.85/tango/tango/text/conv
rt/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 haven't used Tango, but my guess is it's because strings are 
immutable in D2, but used to be mutable in D1.

Jacob Carlborg <doob me.com> writes:

On 2020-09-10 23:00, Paul Backus wrote:

 I haven't used Tango, but my guess is it's because strings are immutable 
 in D2, but used to be mutable in D1.

Tango is compatible with D2. The version of Tango includes the last 
version of DMD it worked on, in this case 2.085.

-- 
/Jacob Carlborg

Jacob Carlborg <doob me.com> writes:

On 2020-09-10 22:55, jeromeG wrote:
 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/conv
rt/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'm guessing `T` should to be `char`. There are some examples at the 
bottom how to use it:

https://github.com/SiegeLord/Tango-D2/blob/6a9efb86a0789fb2e32ef869e647e7de97b5e26b/tango/text/convert/Float.d#L855

-- 
/Jacob Carlborg