Operating system: Darwin-19.0.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 560X OpenGL Engine ATI Technologies Inc. 4.1 ATI-3.2.24
Broken: version: 2.82 (sub 4), branch: master, commit date: 2019-12-09 21:15, hash: rB1a8642937dde
Exact steps for others to reproduce the error
Enter weight paint and the toggle isn't there. It's on the other modes, like Sculpting and Vertex Paint.