Implement _eval_* for Piecewise.
Implement _eval_* for Piecewise.

Implement _eval_conjugate, _eval_evalf, and _eval_power.

moble/sympy,sahmed95/sympy,sampadsaha5/sympy,madan96/sympy,srjoglekar246/sympy,lindsayad/sympy,Curious72/sympy,iamutkarshtiwari/sympy,yashsharan/sympy,hrashk/sympy,Sumith1896/sympy,drufat/sympy,Arafatk/sympy,Gadal/sympy,souravsingh/sympy,Designist/sympy,diofant/diofant,asm666/sympy,wyom/sympy,ahhda/sympy,ga7g08/sympy,Mitchkoens/sympy,grevutiu-gabriel/sympy,sahilshekhawat/sympy,jerli/sympy,cswiercz/sympy,mafiya69/sympy,kaichogami/sympy,jamesblunt/sympy,AunShiLord/sympy,mcdaniel67/sympy,hargup/sympy,aktech/sympy,dqnykamp/sympy,kaushik94/sympy,abhiii5459/sympy,beni55/sympy,Sumith1896/sympy,Davidjohnwilson/sympy,skidzo/sympy,ChristinaZografou/sympy,saurabhjn76/sympy,Davidjohnwilson/sympy,jaimahajan1997/sympy,meghana1995/sympy,sahilshekhawat/sympy,moble/sympy,amitjamadagni/sympy,debugger22/sympy,Arafatk/sympy,shipci/sympy,mcdaniel67/sympy,maniteja123/sympy,Titan-C/sympy,kevalds51/sympy,VaibhavAgarwalVA/sympy,cccfran/sympy,bukzor/sympy,chaffra/sympy,shipci/sympy,skirpichev/omg,sunny94/temp,MridulS/sympy,jerli/sympy,oliverlee/sympy,wanglongqi/sympy,jaimahajan1997/sympy,Shaswat27/sympy,abloomston/sympy,cccfran/sympy,shipci/sympy,toolforger/sympy,Arafatk/sympy,Curious72/sympy,kmacinnis/sympy,chaffra/sympy,Vishluck/sympy,Shaswat27/sympy,AunShiLord/sympy,ahhda/sympy,toolforger/sympy,grevutiu-gabriel/sympy,abhiii5459/sympy,sunny94/temp,liangjiaxing/sympy,kumarkrishna/sympy,ga7g08/sympy,pbrady/sympy,aktech/sympy,abloomston/sympy,jbbskinny/sympy,Shaswat27/sympy,cswiercz/sympy,liangjiaxing/sympy,farhaanbukhsh/sympy,atreyv/sympy,Gadal/sympy,lindsayad/sympy,rahuldan/sympy,sampadsaha5/sympy,grevutiu-gabriel/sympy,kmacinnis/sympy,garvitr/sympy,sampadsaha5/sympy,ChristinaZografou/sympy,atsao72/sympy,yukoba/sympy,garvitr/sympy,sunny94/temp,souravsingh/sympy,lidavidm/sympy,farhaanbukhsh/sympy,toolforger/sympy,dqnykamp/sympy,moble/sympy,saurabhjn76/sympy,souravsingh/sympy,shikil/sympy,hargup/sympy,vipulroxx/sympy,garvitr/sympy,hrashk/sympy,yukoba/sympy,abloomston/sympy,Titan-C/sympy,pbrady/sympy,atreyv/sympy,AkademieOlympia/sympy,meghana1995/sympy,postvakje/sympy,asm666/sympy,rahuldan/sympy,Designist/sympy,jamesblunt/sympy,farhaanbukhsh/sympy,yashsharan/sympy,oliverlee/sympy,kaushik94/sympy,kevalds51/sympy,pbrady/sympy,wyom/sympy,vipulroxx/sympy,AkademieOlympia/sympy,emon10005/sympy,emon10005/sympy,saurabhjn76/sympy,mcdaniel67/sympy,Mitchkoens/sympy,hrashk/sympy,shikil/sympy,atreyv/sympy,yukoba/sympy,kevalds51/sympy,beni55/sympy,abhiii5459/sympy,cccfran/sympy,Vishluck/sympy,Curious72/sympy,wanglongqi/sympy,VaibhavAgarwalVA/sympy,shikil/sympy,skidzo/sympy,debugger22/sympy,MechCoder/sympy,cswiercz/sympy,flacjacket/sympy,iamutkarshtiwari/sympy,lidavidm/sympy,jaimahajan1997/sympy,kmacinnis/sympy,sahmed95/sympy,AunShiLord/sympy,Mitchkoens/sympy,skidzo/sympy,atsao72/sympy,madan96/sympy,kumarkrishna/sympy,MridulS/sympy,debugger22/sympy,rahuldan/sympy,liangjiaxing/sympy,postvakje/sympy,asm666/sympy,mafiya69/sympy,ChristinaZografou/sympy,maniteja123/sympy,yashsharan/sympy,jerli/sympy,postvakje/sympy,kumarkrishna/sympy,hargup/sympy,kaushik94/sympy,pandeyadarsh/sympy,bukzor/sympy,drufat/sympy,meghana1995/sympy,MridulS/sympy,VaibhavAgarwalVA/sympy,sahilshekhawat/sympy,Vishluck/sympy,iamutkarshtiwari/sympy,sahmed95/sympy,vipulroxx/sympy,beni55/sympy,Designist/sympy,chaffra/sympy,madan96/sympy,pandeyadarsh/sympy,emon10005/sympy,drufat/sympy,bukzor/sympy,jamesblunt/sympy,dqnykamp/sympy,lindsayad/sympy,maniteja123/sympy,mafiya69/sympy,Davidjohnwilson/sympy,wanglongqi/sympy,jbbskinny/sympy,atsao72/sympy,kaichogami/sympy,pandeyadarsh/sympy,oliverlee/sympy,aktech/sympy,Titan-C/sympy,lidavidm/sympy,Sumith1896/sympy,wyom/sympy,Gadal/sympy,amitjamadagni/sympy,ahhda/sympy,jbbskinny/sympy,kaichogami/sympy,ga7g08/sympy,AkademieOlympia/sympy,MechCoder/sympy,MechCoder/sympy