v4.0.0

[angularsen]

4.0.0 Release

This PR will serve as the list of items to complete and it will be updated to show the progress before finally merged into master when completed. We all have busy schedules, so if you want to help move this work forward then that is much appreciated!

The main theme is to reduce binary size

In two years it has grown from 280 kB to 1.4 MB and a lot of it is due to unnecessary syntactic sugar with many method overloads for various number types and nullable types - for every of our 800+ units! It simply adds up to a big total.

These items are chosen from #180, trying to include as many of the low hanging fruits as possible, while still keeping the list short and realistic to complete in a reasonably short time - we are all busy in our daily lives. We can always have more major version bumps later than trying to perfect it all now.

Feature complete before November, merged before mid-December

I would like to aim for a "beta" pre-release nuget sometime in October with all the items completed, so we can have some time to test it before releasing the final, stable 4.0.0 version before Christmas holidays.
We should have the work items list more or less final before Monday, October 8th.

Changes

Added

• UnitSystem with a different meaning, now defines the base units for a unit system (Si unit system #524)

Removed

• Replace netstandard1.0 target with netstandard2.0, to avoid the extra dependencies (Add netstandard 2.0 target #477)
• Remove code marked as [Obsolete], such as VolumeUnit.Teaspoon (Removing obsolete quantity units #490)
• Remove nullable From factory methods (Removing nullable methods from quantity classes as well as extension … #483)
• Remove extension methods on nullable number types (Removing nullable methods from quantity classes as well as extension … #483)
• Remove all number extension methods (Remove all number extension methods #497)
• Remove Length2d, replaced by Area (Remove Length2d #501)
• Remove static methods on UnitSystem, should use UnitSystem.Default instead (Remove UnitSystem static methods #496)
• Remove unit parameter from ToString() methods (Removing unit conversion from ToString methods. ToUnit must be called… #546)

Changed

• Throw exception on NaN values in static constructor methods, like FromMeters() (Do not allow NaN or Infinity #502, see Support NaN #176 (comment))
• Throw if unit was not specified when constructing quantities, (Adding ArgumentException to quantity if constructed with Undefned val… #499 - Preserve value and unit #389 (comment))
• Stricter parsing ("Length.TryParse" parses invalid values #343 and v5: Wishlist for breaking changes #180 (comment))
• Remove unit parameter from ToString() methods (Removing unit conversion from ToString methods. ToUnit must be called… #546)
• Change Temperature arithmetic back to use base unit Kelvin (Normalize Temperature arithmetic #550, see Temperature times a double #518)

Renamed

• Correct SingularName for some Flow unit definitions (Fix SingularName for some units in VolumeFlow #494, see Add more Flow units #360)
• Split/rename UnitSystem into UnitParser, GlobalConfiguration, UnitAbbreviationsCache (Splitting UnitSystem class into more focused classes #511)

Fixed

• Search for any TODO comments in the code to address, remove comment and either fix or create issue (5d24432)
• Update README with v4 changes Update README with v4 changes #498
• Do not try/catch in UnitConverter.Try-methods (Try methods without catch #506)
• Do not try/catch in Length.TryParse() and for other quantities (Try parse #507)
• Add/update changelog in wiki for v4 with some summary copied from this issue, some v3 to v4 migration instructions and briefly explain why some stuff were removed

Milestones

• Finalize work items list (Monday, October 8)
• Release 4.0.0-beta1, feature complete (Wednesday, October 31)
• Show release notes and upgrade guide when upgrading to 4.x nuget, if possible
• Release 4.0.0 (Monday, December 17)

[angularsen]

Reverted #550 in 71bc0a8.

Per discussion in:
#560 (comment)

We can't justify this change just yet, we need to know if the majority of our userbase expects this new Temperature arithmetic or the old one.

[angularsen]

4.0.0-beta2 released.