treat String as immutable in ===. part of #22193

[JeffBezanson]

This is potentially unsafe if somebody assumes that ismutable(a) && a === b implies pointer(a) == pointer(b). Hopefully in contexts where that matters you would just look at pointer(a) directly.

[tkelman]

should these be different lengths 32 vs 64?

[JeffBezanson]

For whatever reason, both functions take a uint32 seed.

[StefanKarpinski]

LGTM. Surprisingly small, simple change.

[tkelman]

@nanosoldier runbenchmarks(ALL, vs=":master")

[nanosoldier]

Your benchmark job has completed - possible performance regressions were detected. A full report can be found here. cc @ararslan

[ararslan]

Nanosoldier's table reproduced with formatting fixed:

ID	time ratio	memory ratio
["array","convert",("Float64","Int")]	0.81 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivCopy!",1000)]	0.79 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivCopy!",250)]	0.80 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivCopy!",500)]	0.78 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivSub!",1000)]	0.80 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivSub!",250)]	0.85 (15%) ✅	1.00 (1%)
["array","subarray",("lucompletepivSub!",500)]	0.80 (15%) ✅	1.00 (1%)
["misc","splatting",(3,3,3)]	0.85 (15%) ✅	1.00 (1%)
["problem","laplacian","laplace_iter_vec"]	0.80 (15%) ✅	1.00 (1%)
["problem","stockcorr","stockcorr"]	0.83 (15%) ✅	1.00 (1%)
["scalar","mod2pi",("argument reduction (easy) abs(x) < 2.0^20π/4","positive argument","Float64")]	0.82 (15%) ✅	1.00 (1%)
["scalar","mod2pi",("argument reduction (easy) abs(x) < 9π/4","negative argument","Float64")]	0.84 (15%) ✅	1.00 (1%)
["scalar","mod2pi",("argument reduction (easy) abs(x) > 2.0^20*π/2","negative argument","Float64")]	1.24 (15%) ❌	1.00 (1%)
["scalar","mod2pi",("argument reduction (easy) abs(x) > 2.0^20*π/2","positive argument","Float64")]	1.28 (15%) ❌	1.00 (1%)
["scalar","rem_pio2",("argument reduction (easy) abs(x) < 2π/4","positive argument","Float64")]	1.18 (15%) ❌	1.00 (1%)
["scalar","rem_pio2",("argument reduction (easy) abs(x) < 9π/4","negative argument","Float64")]	0.85 (15%) ✅	1.00 (1%)
["scalar","rem_pio2",("argument reduction (easy) abs(x) < 9π/4","positive argument","Float64")]	1.18 (15%) ❌	1.00 (1%)
["scalar","rem_pio2",("argument reduction (hard) abs(x) < 2π/4","negative argument","Float64")]	1.16 (15%) ❌	1.00 (1%)
["scalar","rem_pio2",("argument reduction (paynehanek) abs(x) > 2.0^20*π/2","negative argument","Float64")]	1.23 (15%) ❌	1.00 (1%)
["scalar","rem_pio2",("argument reduction (paynehanek) abs(x) > 2.0^20*π/2","positive argument","Float64")]	1.21 (15%) ❌	1.00 (1%)
["tuple","reduction",("sum",(16,16))]	0.85 (15%) ✅	1.00 (1%)