# unit.h

unit.h is a simple library for working with units and dimensioned quantities in C.

To use it, simply copy the `unit.h` file into your project and include it where necessary. 
You must also define the `UNITH_IMPL` macro before importing it in one file so the 
implementation is compiled.

## Working with dimensioned quantities

unit.h provides the U-macro, which accepts a string representing a unit or compound 
unit and returns the conversion ratio between it and the corresponding SI unit. This 
conversion ratio can be used to construct dimensioned quantities like so:

```
double water_density = 1.0 * U("g/cm^3");
```

Likewise, the UFMT and UARG macros can be used with `printf` to display these quantities 
like so:

```
printf("The density of water is " UFMT ".\n", UARG(water_density, "kg/m^3"));
```

## Unit Strings

Units are defined as c-strings. Each string consists of a series of unit names separated 
by whitespace, each unit may be raised to an arbitrary (non-)integer power with a 
`^`. There may also be a single slash among the units, which negates the exponenents 
of all following units.

In the case where there are no units before the slash, the number 1 must be used 
before it instead: "1/cm^3".

## Misc. Notes

Angular measurements are internally represented using radians and steradians so they 
can work with trigonometric functions.

SI prefixes may be used before unit names. (E.g. "Mm" is a megameter.)