Is there something special required to use Appender.clear

[Ali Çehreli]

On 01/24/2019 04:35 AM, FeepingCreature wrote:
 > On Tuesday, 27 March 2018 at 12:31:05 UTC, Simen Kjærås wrote:
 >> On Tuesday, 27 March 2018 at 12:17:58 UTC, Ellie Harper wrote:
 >>> Sorry if this is a stupid question, but is there something special
 >>> required to call Appender.clear?  When I attempt even just a simple
 >>> use I am getting compile errors relating to `template object.clear`.
 >>
 >> From the documentation for Appender:
 >>
 >>> Note
 >>> clear is disabled for immutable or const element types, due to the
 >>> possibility that Appender might overwrite immutable data.
 >>
 >> Since string is immutable(char)[], clear() is simply not available for
 >> appender!string.
 >>
 >> --
 >>   Simen
 >
 > Isn't this wrong, though? Appender controls the memory it references. It
 > could just choose to allocate non-immutable memory internally. As long
 > as any const data put into the appender is *returned* as const, there is
 > no chance of immutable memory being overwritten.

I think Appender is trying to protect previous data from Appender's 
later use. If it handed out immutable data, the user is expecting it to 
not change. So, Appender cannot clear it for later use.

Ali