Dezimalfestkommazahlrechnung

Features

• Basic unsigned fixed-point arithmetic
• Wrapper types implementing arithmetic traits for convenience, see [UDf64Checked] and [UDf64Saturating]
• up to 19 effective decimal digits (integer part and fractional combined)
• #![no_std] compatible, no runtime dependencies except core (except for some tests)
• No heap allocations
• Written in straightforward safe Rust, accompanied by an extensive automated test suite
• Display

Planned features:

• signed type
• TryFrom<&str>, FromStr
• narrowing/widening casts

Possible future features:

• approximations for:
  • square root, higher order roots
  • exp, log
  • trig functions
• conversion to/from float
• NonZero variants
• u32-based variants
• localized Display/parse

Non- and anti-goals:

• Choosing precision/width at runtime
• Unchecked/wrapping or panicking API (just use .unwrap())
• Performance: All basic operations are implemented with a handful of operations on u64 or u128 (and overflow checks), so performance should be decent. I don't care enough to make benchmarks though.