rollup merge of #20214: bluss/fix-hashmap-example
rollup merge of #20214: bluss/fix-hashmap-example

The example derived Hash + Eq on a type that was used as *values* for
a hashmap.. for the example to make sense, we have to use a custom *key*
type.

Write a slightly more involved example, still using Vikings, but this
time as key.

I preferred using String over &str here, since that's the typical usage
and we might want to lead users down that path.

aepsil0n/rust,dinfuehr/rust,jroesch/rust,XMPPwocky/rust,aidancully/rust,andars/rust,kwantam/rust,rprichard/rust,hauleth/rust,ebfull/rust,aidancully/rust,robertg/rust,aidancully/rust,krzysz00/rust,ejjeong/rust,nwin/rust,ejjeong/rust,untitaker/rust,ruud-v-a/rust,jroesch/rust,ejjeong/rust,miniupnp/rust,jroesch/rust,TheNeikos/rust,zachwick/rust,pelmers/rust,zubron/rust,jashank/rust,rohitjoshi/rust,AerialX/rust,dwillmer/rust,krzysz00/rust,pelmers/rust,zaeleus/rust,zubron/rust,graydon/rust,pelmers/rust,TheNeikos/rust,zachwick/rust,bombless/rust-docs-chinese,mdinger/rust,seanrivera/rust,avdi/rust,jashank/rust,kimroen/rust,KokaKiwi/rust,reem/rust,rohitjoshi/rust,avdi/rust,nwin/rust,pshc/rust,ktossell/rust,victorvde/rust,zubron/rust,robertg/rust,sae-bom/rust,victorvde/rust,mihneadb/rust,pshc/rust,jashank/rust,defuz/rust,vhbit/rust,ktossell/rust,dinfuehr/rust,defuz/rust,bombless/rust,zubron/rust,mihneadb/rust,reem/rust,aidancully/rust,GBGamer/rust,carols10cents/rust,mihneadb/rust,ruud-v-a/rust,ktossell/rust,zaeleus/rust,sae-bom/rust,GBGamer/rust,victorvde/rust,ejjeong/rust,ktossell/rust,andars/rust,vhbit/rust,sae-bom/rust,hauleth/rust,bombless/rust,hauleth/rust,jashank/rust,ruud-v-a/rust,mdinger/rust,kimroen/rust,vhbit/rust,krzysz00/rust,andars/rust,hauleth/rust,bombless/rust,XMPPwocky/rust,ebfull/rust,l0kod/rust,dwillmer/rust,vhbit/rust,mihneadb/rust,mvdnes/rust,zachwick/rust,andars/rust,richo/rust,l0kod/rust,defuz/rust,robertg/rust,graydon/rust,TheNeikos/rust,aepsil0n/rust,l0kod/rust,mihneadb/rust,carols10cents/rust,dinfuehr/rust,rohitjoshi/rust,aneeshusa/rust,aidancully/rust,omasanori/rust,carols10cents/rust,gifnksm/rust,AerialX/rust-rt-minimal,gifnksm/rust,XMPPwocky/rust,nwin/rust,gifnksm/rust,jashank/rust,miniupnp/rust,jroesch/rust,mdinger/rust,kimroen/rust,ruud-v-a/rust,gifnksm/rust,rprichard/rust,rohitjoshi/rust,nwin/rust,aepsil0n/rust,jroesch/rust,pshc/rust,dinfuehr/rust,rprichard/rust,cllns/rust,philyoon/rust,AerialX/rust-rt-minimal,pelmers/rust,jroesch/rust,vhbit/rust,mdinger/rust,rprichard/rust,l0kod/rust,pshc/rust,carols10cents/rust,GBGamer/rust,omasanori/rust,rohitjoshi/rust,defuz/rust,kwantam/rust,mvdnes/rust,defuz/rust,aneeshusa/rust,AerialX/rust,dinfuehr/rust,untitaker/rust,graydon/rust,zubron/rust,reem/rust,krzysz00/rust,dwillmer/rust,ejjeong/rust,AerialX/rust,miniupnp/rust,miniupnp/rust,rprichard/rust,robertg/rust,KokaKiwi/rust,kimroen/rust,sae-bom/rust,pshc/rust,avdi/rust,aepsil0n/rust,miniupnp/rust,kwantam/rust,jashank/rust,defuz/rust,zachwick/rust,XMPPwocky/rust,jashank/rust,untitaker/rust,seanrivera/rust,jroesch/rust,KokaKiwi/rust,cllns/rust,zaeleus/rust,richo/rust,GBGamer/rust,omasanori/rust,avdi/rust,dwillmer/rust,kwantam/rust,kwantam/rust,seanrivera/rust,GBGamer/rust,zubron/rust,vhbit/rust,miniupnp/rust,miniupnp/rust,kimroen/rust,jroesch/rust,mdinger/rust,ruud-v-a/rust,krzysz00/rust,AerialX/rust-rt-minimal,zachwick/rust,aneeshusa/rust,reem/rust,mihneadb/rust,ebfull/rust,reem/rust,richo/rust,bombless/rust,nwin/rust,nwin/rust,graydon/rust,sae-bom/rust,XMPPwocky/rust,ktossell/rust,nwin/rust,robertg/rust,richo/rust,zubron/rust,l0kod/rust,GBGamer/rust,philyoon/rust,andars/rust,TheNeikos/rust,AerialX/rust-rt-minimal,ktossell/rust,AerialX/rust,mvdnes/rust,zaeleus/rust,omasanori/rust,ebfull/rust,ktossell/rust,kwantam/rust,dinfuehr/rust,dwillmer/rust,untitaker/rust,richo/rust,aneeshusa/rust,ruud-v-a/rust,rprichard/rust,vhbit/rust,vhbit/rust,omasanori/rust,carols10cents/rust,omasanori/rust,GBGamer/rust,victorvde/rust,victorvde/rust,zaeleus/rust,mahkoh/rust,dwillmer/rust,AerialX/rust-rt-minimal,robertg/rust,cllns/rust,bombless/rust,mahkoh/rust,hauleth/rust,ebfull/rust,graydon/rust,ejjeong/rust,GBGamer/rust,zaeleus/rust,mahkoh/rust,mahkoh/rust,krzysz00/rust,KokaKiwi/rust,l0kod/rust,aneeshusa/rust,avdi/rust,mvdnes/rust,kimroen/rust,XMPPwocky/rust,kimroen/rust,seanrivera/rust,reem/rust,aneeshusa/rust,pshc/rust,zubron/rust,aepsil0n/rust,pshc/rust,hauleth/rust,philyoon/rust,pshc/rust,graydon/rust,l0kod/rust,untitaker/rust,AerialX/rust,aidancully/rust,andars/rust,sae-bom/rust,mahkoh/rust,richo/rust,aepsil0n/rust,philyoon/rust,gifnksm/rust,dwillmer/rust,avdi/rust,zachwick/rust,rohitjoshi/rust,mvdnes/rust,mvdnes/rust,bombless/rust,TheNeikos/rust,pelmers/rust,gifnksm/rust,seanrivera/rust,cllns/rust,nwin/rust,carols10cents/rust,dwillmer/rust,jashank/rust,untitaker/rust,miniupnp/rust,l0kod/rust,AerialX/rust-rt-minimal,mdinger/rust,philyoon/rust,seanrivera/rust,mahkoh/rust,cllns/rust,TheNeikos/rust,AerialX/rust,pelmers/rust,ebfull/rust,philyoon/rust,victorvde/rust,cllns/rust,KokaKiwi/rust,KokaKiwi/rust