docs: examples line numbers fixed

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Mateusz Pusz
2024-09-17 16:11:19 -06:00
parent 7ce8d695b1
commit 80880f1014
3 changed files with 54 additions and 46 deletions

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@ -7,7 +7,7 @@ tags:
# `avg_speed`
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/TnqGa4sdn)"
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/v9c5T6bc4)"
Let's continue the previous example. This time, our purpose will not be to showcase as many
library features as possible, but we will scope on different interfaces one can provide
@ -18,28 +18,28 @@ First, we either import a module or include all the necessary header files and i
the identifiers from the `mp_units` namespace:
```cpp title="avg_speed.cpp" linenums="1"
--8<-- "example/avg_speed.cpp:28:42"
--8<-- "example/avg_speed.cpp:28:46"
```
Next, we define two functions calculating average speed based on quantities of fixed units
and integral and floating-point representation types, respectively, and a third function
that we introduced in the [previous example](hello_units.md):
```cpp title="avg_speed.cpp" linenums="16"
--8<-- "example/avg_speed.cpp:44:58"
```cpp title="avg_speed.cpp" linenums="20"
--8<-- "example/avg_speed.cpp:48:62"
```
We also added a simple utility to print our results:
```cpp title="avg_speed.cpp" linenums="31"
--8<-- "example/avg_speed.cpp:60:66"
```cpp title="avg_speed.cpp" linenums="35"
--8<-- "example/avg_speed.cpp:64:70"
```
Now, let's analyze how those three utility functions behave with different sets of arguments.
First, we are going to use quantities of SI units and integral representation:
```cpp title="avg_speed.cpp" linenums="38"
--8<-- "example/avg_speed.cpp:68:82"
```cpp title="avg_speed.cpp" linenums="42"
--8<-- "example/avg_speed.cpp:72:86"
```
The above provides the following output:
@ -61,8 +61,8 @@ representation types (the resulting speed is `108 km/h`).
The second scenario is really similar to the previous one, but this time, function arguments
have floating-point representation types:
```cpp title="avg_speed.cpp" linenums="53"
--8<-- "example/avg_speed.cpp:84:95"
```cpp title="avg_speed.cpp" linenums="57"
--8<-- "example/avg_speed.cpp:88:99"
```
Conversion from floating-point to integral representation types is
@ -82,8 +82,8 @@ Average speed of a car that makes 220 km in 2 h is 110 km/h.
Next, let's do the same for integral and floating-point representations, but this time
using international mile:
```cpp title="avg_speed.cpp" linenums="65"
--8<-- "example/avg_speed.cpp:97:129"
```cpp title="avg_speed.cpp" linenums="69"
--8<-- "example/avg_speed.cpp:101:132"
```
One important difference here is the fact that as it is not possible to make a lossless conversion
@ -108,8 +108,8 @@ Please note how the first and third results get truncated using integral represe
In the end, we repeat the scenario for CGS units:
```cpp title="avg_speed.cpp" linenums="97"
--8<-- "example/avg_speed.cpp:131:161"
```cpp title="avg_speed.cpp" linenums="101"
--8<-- "example/avg_speed.cpp:134:165"
```
Again, we observe `value_cast` being used in the same places and consistent truncation errors
@ -129,6 +129,6 @@ Average speed of a car that makes 2.2e+07 cm in 7200 s is 110 km/h.
The example file ends with a simple `main()` function:
```cpp title="avg_speed.cpp" linenums="128"
--8<-- "example/avg_speed.cpp:163:"
```cpp title="avg_speed.cpp" linenums="133"
--8<-- "example/avg_speed.cpp:167:"
```

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@ -6,32 +6,32 @@ tags:
# `hello_units`
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/bT4GGPbef)"
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/MYn5qjPzh)"
This is a really simple example showcasing the features of the **mp-units** library.
First, we either import the `mp_units` module or include the headers for:
- an International System of Quantities (ISQ)
- an International System of units (SI)
- units derived from the International Yard and Pound
- text formatting and stream output support
- an International System of Quantities (ISQ),
- an International System of units (SI),
- units derived from the International Yard and Pound,
- text formatting and stream output support.
```cpp title="hello_units.cpp" linenums="1"
--8<-- "example/hello_units.cpp:28:41"
--8<-- "example/hello_units.cpp:28:45"
```
Also, to shorten the definitions, we "import" all the symbols from the `mp_units` namespace.
```cpp title="hello_units.cpp" linenums="14"
--8<-- "example/hello_units.cpp:42:43"
```cpp title="hello_units.cpp" linenums="18"
--8<-- "example/hello_units.cpp:46:47"
```
Next, we define a simple function that calculates the average speed based on the provided
arguments of length and time:
```cpp title="hello_units.cpp" linenums="15"
--8<-- "example/hello_units.cpp:44:47"
```cpp title="hello_units.cpp" linenums="19"
--8<-- "example/hello_units.cpp:48:51"
```
The above function template takes any quantities implicitly convertible to `isq::length`
@ -45,37 +45,37 @@ that its quantity type is implicitly convertible to `isq::speed`.
type is beneficial for users of such a function as it provides more information
of what to expect from a function than just using `auto`.
```cpp title="hello_units.cpp" linenums="19"
--8<-- "example/hello_units.cpp:49:52"
```cpp title="hello_units.cpp" linenums="23"
--8<-- "example/hello_units.cpp:53:56"
```
The above lines explicitly opt into using unit symbols from two systems of units.
As this introduces a lot of short identifiers into the current scope, it is not done
implicitly while including a header file.
```cpp title="hello_units.cpp" linenums="23"
--8<-- "example/hello_units.cpp:54:60"
```cpp title="hello_units.cpp" linenums="27"
--8<-- "example/hello_units.cpp:58:64"
```
- Lines `23` & `24` create a quantity of kind `isq::length / isq::time` with the numbers
- Lines `27` & `28` create a quantity of kind `isq::length / isq::time` with the numbers
and units provided. Such quantities can be converted or assigned to any other quantity
with a matching kind.
- Line `25` calls our function template with quantities of kind `isq::length` and
- Line `29` calls our function template with quantities of kind `isq::length` and
`isq::time` and number and units provided.
- Line `26` explicitly provides quantity types of the quantities passed to a function template.
- Line `30` explicitly provides quantity types of the quantities passed to a function template.
This time, those will not be quantity kinds anymore and will have
[more restrictive conversion rules](../framework_basics/simple_and_typed_quantities.md#quantity_cast-to-force-unsafe-conversions).
- Line `27` changes the unit of a quantity `v3` to `m / s` in a
- Line `31` changes the unit of a quantity `v3` to `m / s` in a
[value-preserving way](../framework_basics/value_conversions.md#value-preserving-conversions)
(floating-point representations are considered to be value-preserving).
- Line `28` does a similar operation, but this time, it would also succeed for
- Line `32` does a similar operation, but this time, it would also succeed for
[value-truncating cases](../framework_basics/value_conversions.md#value-truncating-conversions)
(if that was the case).
- Line `29` does a [value-truncating conversion](../framework_basics/value_conversions.md#value-truncating-conversions)
- Line `33` does a [value-truncating conversion](../framework_basics/value_conversions.md#value-truncating-conversions)
of changing the underlying representation type from `double` to `int`.
```cpp title="hello_units.cpp" linenums="30"
--8<-- "example/hello_units.cpp:62"
```cpp title="hello_units.cpp" linenums="34"
--8<-- "example/hello_units.cpp:66"
```
The above presents [various ways to print a quantity](../framework_basics/text_output.md).
@ -86,3 +86,6 @@ Both stream insertion operations and `std::format` facilities are supported.
`MP_UNITS_STD_FMT` is used for compatibility reasons. If a specific compiler
does not support `std::format` or a user prefers to use the `{fmt}` library, this macro
will resolve to `fmt` namespace. Otherwise, the `std` namespace will be used.
More about it can be found in the [Wide Compatibility](../use_cases/wide_compatibility.md#mp_units_std_fmt)
chapter.

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@ -6,7 +6,7 @@ tags:
# `si_constants`
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/MevcK8vYT)"
!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/eGqbW5d8K)"
The next example presents all the seven defining constants of the SI system. We can observe
how [Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md)
@ -22,15 +22,20 @@ the simplicity of this example, we
to be able to express vector quantities with simple scalar types.
```cpp title="si_constants.cpp" linenums="14"
--8<-- "example/si_constants.cpp:42:"
--8<-- "example/si_constants.cpp:42:44"
```
The main part of the example prints all of the SI-defining constants. While analyzing the output of
this program (provided below), we can easily notice that a direct printing of the quantity provides
just a value `1` with a proper constant symbol. This is the main power of the
[Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md) feature.
Only after we explicitly convert the unit of a quantity to proper SI units we get an actual numeric
value of the constant.
The main part of the example prints all of the SI-defining constants:
```cpp title="si_constants.cpp" linenums="17"
--8<-- "example/si_constants.cpp:45:"
```
While analyzing the output of this program (provided below), we can easily notice that a direct
printing of the quantity provides just a value `1` with a proper constant symbol. This is the main
power of the [Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md)
feature. Only after we explicitly convert the unit of a quantity to proper SI units we get an
actual numeric value of the constant.
```text
The seven defining constants of the SI and the seven corresponding units they define: