add WriteBytesAsString()

[lavalamp]

I have a situation where I'm constructing key names, and I want to avoid an allocation; I can do this cast in my code, but I thought I'd see if there's interest in accepting this so it's obvious for other people how to do this?

[codecov]

Codecov Report

Merging #393 into master will decrease coverage by 0.11%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #393      +/-   ##
=========================================
- Coverage   81.81%   81.7%   -0.12%     
=========================================
  Files          41      41              
  Lines        5022    5024       +2     
=========================================
- Hits         4109    4105       -4     
- Misses        792     798       +6     
  Partials      121     121

Impacted Files	Coverage Δ
reflect_struct_encoder.go	88.98% <100%> (ø)	⬆️
stream_str.go	94.17% <100%> (+0.11%)	⬆️
reflect_struct_decoder.go	48.32% <0%> (-0.84%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 27518f6...41a54ea. Read the comment docs.

[taowen]

I prefer to keep the casting in user code.