2158f88f1d Add a method to `pow::Target` for returning difficulty as an f64. (junderw)
Pull request description:
Closes#1703
This adds a conversion function to U256 to get an f64. We use the method shown in the following blog post.
https://blog.m-ou.se/floats/
Target::MAX was converted to a f64 and set as a const that is verified in a unit test.
The code is rather confusing, so I took a crack at explaining it in my comments as well. Please let me know if you want it cleaned up some more.
ACKs for top commit:
apoelstra:
ACK 2158f88f1d
tcharding:
ACK 2158f88f1d
Tree-SHA512: 7c0e82bd1756950c1c6dfb9da91fd71b276e2e7dc8a33e69112f87b87e358240f0f7c4894d24ab228e149d862938833a2e65e345ce2712a78dc86dec197da34f