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docs: examples line numbers fixed
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@ -7,7 +7,7 @@ tags:
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# `avg_speed`
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/TnqGa4sdn)"
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/v9c5T6bc4)"
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Let's continue the previous example. This time, our purpose will not be to showcase as many
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library features as possible, but we will scope on different interfaces one can provide
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@ -18,28 +18,28 @@ First, we either import a module or include all the necessary header files and i
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the identifiers from the `mp_units` namespace:
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```cpp title="avg_speed.cpp" linenums="1"
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--8<-- "example/avg_speed.cpp:28:42"
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--8<-- "example/avg_speed.cpp:28:46"
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```
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Next, we define two functions calculating average speed based on quantities of fixed units
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and integral and floating-point representation types, respectively, and a third function
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that we introduced in the [previous example](hello_units.md):
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```cpp title="avg_speed.cpp" linenums="16"
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--8<-- "example/avg_speed.cpp:44:58"
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```cpp title="avg_speed.cpp" linenums="20"
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--8<-- "example/avg_speed.cpp:48:62"
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```
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We also added a simple utility to print our results:
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```cpp title="avg_speed.cpp" linenums="31"
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--8<-- "example/avg_speed.cpp:60:66"
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```cpp title="avg_speed.cpp" linenums="35"
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--8<-- "example/avg_speed.cpp:64:70"
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```
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Now, let's analyze how those three utility functions behave with different sets of arguments.
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First, we are going to use quantities of SI units and integral representation:
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```cpp title="avg_speed.cpp" linenums="38"
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--8<-- "example/avg_speed.cpp:68:82"
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```cpp title="avg_speed.cpp" linenums="42"
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--8<-- "example/avg_speed.cpp:72:86"
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```
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The above provides the following output:
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@ -61,8 +61,8 @@ representation types (the resulting speed is `108 km/h`).
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The second scenario is really similar to the previous one, but this time, function arguments
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have floating-point representation types:
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```cpp title="avg_speed.cpp" linenums="53"
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--8<-- "example/avg_speed.cpp:84:95"
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```cpp title="avg_speed.cpp" linenums="57"
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--8<-- "example/avg_speed.cpp:88:99"
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```
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Conversion from floating-point to integral representation types is
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@ -82,8 +82,8 @@ Average speed of a car that makes 220 km in 2 h is 110 km/h.
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Next, let's do the same for integral and floating-point representations, but this time
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using international mile:
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```cpp title="avg_speed.cpp" linenums="65"
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--8<-- "example/avg_speed.cpp:97:129"
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```cpp title="avg_speed.cpp" linenums="69"
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--8<-- "example/avg_speed.cpp:101:132"
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```
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One important difference here is the fact that as it is not possible to make a lossless conversion
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@ -108,8 +108,8 @@ Please note how the first and third results get truncated using integral represe
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In the end, we repeat the scenario for CGS units:
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```cpp title="avg_speed.cpp" linenums="97"
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--8<-- "example/avg_speed.cpp:131:161"
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```cpp title="avg_speed.cpp" linenums="101"
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--8<-- "example/avg_speed.cpp:134:165"
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```
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Again, we observe `value_cast` being used in the same places and consistent truncation errors
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@ -129,6 +129,6 @@ Average speed of a car that makes 2.2e+07 cm in 7200 s is 110 km/h.
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The example file ends with a simple `main()` function:
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```cpp title="avg_speed.cpp" linenums="128"
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--8<-- "example/avg_speed.cpp:163:"
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```cpp title="avg_speed.cpp" linenums="133"
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--8<-- "example/avg_speed.cpp:167:"
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```
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@ -6,32 +6,32 @@ tags:
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# `hello_units`
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/bT4GGPbef)"
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/MYn5qjPzh)"
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This is a really simple example showcasing the features of the **mp-units** library.
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First, we either import the `mp_units` module or include the headers for:
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- an International System of Quantities (ISQ)
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- an International System of units (SI)
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- units derived from the International Yard and Pound
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- text formatting and stream output support
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- an International System of Quantities (ISQ),
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- an International System of units (SI),
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- units derived from the International Yard and Pound,
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- text formatting and stream output support.
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```cpp title="hello_units.cpp" linenums="1"
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--8<-- "example/hello_units.cpp:28:41"
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--8<-- "example/hello_units.cpp:28:45"
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```
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Also, to shorten the definitions, we "import" all the symbols from the `mp_units` namespace.
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```cpp title="hello_units.cpp" linenums="14"
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--8<-- "example/hello_units.cpp:42:43"
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```cpp title="hello_units.cpp" linenums="18"
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--8<-- "example/hello_units.cpp:46:47"
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```
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Next, we define a simple function that calculates the average speed based on the provided
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arguments of length and time:
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```cpp title="hello_units.cpp" linenums="15"
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--8<-- "example/hello_units.cpp:44:47"
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```cpp title="hello_units.cpp" linenums="19"
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--8<-- "example/hello_units.cpp:48:51"
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```
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The above function template takes any quantities implicitly convertible to `isq::length`
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@ -45,37 +45,37 @@ that its quantity type is implicitly convertible to `isq::speed`.
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type is beneficial for users of such a function as it provides more information
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of what to expect from a function than just using `auto`.
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```cpp title="hello_units.cpp" linenums="19"
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--8<-- "example/hello_units.cpp:49:52"
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```cpp title="hello_units.cpp" linenums="23"
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--8<-- "example/hello_units.cpp:53:56"
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```
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The above lines explicitly opt into using unit symbols from two systems of units.
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As this introduces a lot of short identifiers into the current scope, it is not done
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implicitly while including a header file.
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```cpp title="hello_units.cpp" linenums="23"
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--8<-- "example/hello_units.cpp:54:60"
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```cpp title="hello_units.cpp" linenums="27"
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--8<-- "example/hello_units.cpp:58:64"
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```
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- Lines `23` & `24` create a quantity of kind `isq::length / isq::time` with the numbers
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- Lines `27` & `28` create a quantity of kind `isq::length / isq::time` with the numbers
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and units provided. Such quantities can be converted or assigned to any other quantity
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with a matching kind.
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- Line `25` calls our function template with quantities of kind `isq::length` and
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- Line `29` calls our function template with quantities of kind `isq::length` and
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`isq::time` and number and units provided.
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- Line `26` explicitly provides quantity types of the quantities passed to a function template.
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- Line `30` explicitly provides quantity types of the quantities passed to a function template.
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This time, those will not be quantity kinds anymore and will have
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[more restrictive conversion rules](../framework_basics/simple_and_typed_quantities.md#quantity_cast-to-force-unsafe-conversions).
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- Line `27` changes the unit of a quantity `v3` to `m / s` in a
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- Line `31` changes the unit of a quantity `v3` to `m / s` in a
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[value-preserving way](../framework_basics/value_conversions.md#value-preserving-conversions)
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(floating-point representations are considered to be value-preserving).
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- Line `28` does a similar operation, but this time, it would also succeed for
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- Line `32` does a similar operation, but this time, it would also succeed for
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[value-truncating cases](../framework_basics/value_conversions.md#value-truncating-conversions)
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(if that was the case).
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- Line `29` does a [value-truncating conversion](../framework_basics/value_conversions.md#value-truncating-conversions)
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- Line `33` does a [value-truncating conversion](../framework_basics/value_conversions.md#value-truncating-conversions)
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of changing the underlying representation type from `double` to `int`.
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```cpp title="hello_units.cpp" linenums="30"
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--8<-- "example/hello_units.cpp:62"
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```cpp title="hello_units.cpp" linenums="34"
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--8<-- "example/hello_units.cpp:66"
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```
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The above presents [various ways to print a quantity](../framework_basics/text_output.md).
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@ -86,3 +86,6 @@ Both stream insertion operations and `std::format` facilities are supported.
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`MP_UNITS_STD_FMT` is used for compatibility reasons. If a specific compiler
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does not support `std::format` or a user prefers to use the `{fmt}` library, this macro
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will resolve to `fmt` namespace. Otherwise, the `std` namespace will be used.
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More about it can be found in the [Wide Compatibility](../use_cases/wide_compatibility.md#mp_units_std_fmt)
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chapter.
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@ -6,7 +6,7 @@ tags:
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# `si_constants`
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/MevcK8vYT)"
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!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/eGqbW5d8K)"
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The next example presents all the seven defining constants of the SI system. We can observe
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how [Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md)
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@ -22,15 +22,20 @@ the simplicity of this example, we
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to be able to express vector quantities with simple scalar types.
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```cpp title="si_constants.cpp" linenums="14"
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--8<-- "example/si_constants.cpp:42:"
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--8<-- "example/si_constants.cpp:42:44"
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```
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The main part of the example prints all of the SI-defining constants. While analyzing the output of
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this program (provided below), we can easily notice that a direct printing of the quantity provides
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just a value `1` with a proper constant symbol. This is the main power of the
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[Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md) feature.
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Only after we explicitly convert the unit of a quantity to proper SI units we get an actual numeric
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value of the constant.
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The main part of the example prints all of the SI-defining constants:
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```cpp title="si_constants.cpp" linenums="17"
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--8<-- "example/si_constants.cpp:45:"
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```
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While analyzing the output of this program (provided below), we can easily notice that a direct
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printing of the quantity provides just a value `1` with a proper constant symbol. This is the main
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power of the [Faster-than-lightspeed Constants](../framework_basics/faster_than_lightspeed_constants.md)
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feature. Only after we explicitly convert the unit of a quantity to proper SI units we get an
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actual numeric value of the constant.
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```text
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The seven defining constants of the SI and the seven corresponding units they define:
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