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108 lines
3.3 KiB
Markdown
108 lines
3.3 KiB
Markdown
---
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title: "to_string"
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---
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{{< callout type="info">}}
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Header: `to_string.h`
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{{< /callout >}}
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Functions that will render a text representation of bools, integrals, floating point, strings, string views and pointers.
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Uses `etl::basic_format_spec` to define the required formatting.
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It will convert to any of the ETL string types.
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## Default format specification
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Where `StringType` is `etl::istring`, `etl::iwstring`, `etl::iu8string`, `etl::iu16string` or `etl::iu32string`.
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```cpp
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template <typename T>
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const StringType& to_string(const T value,
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StringType& str,
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const bool append = false)
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```
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---
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```cpp
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template <typename T> // Where T is an integral
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const StringType& to_string(const T value,
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uint32_t denominator_exponent,
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StringType& str,
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const bool append = false)
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```
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`value` The value to convert to a string.
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`str` The string in with to place the rendered text.
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`append` If true then appends the text to the current string's content. Default `false`.
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From: `20.17.0`
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## Supplied format specification
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Where `StringType` is `etl::istring`, `etl::iwstring`, `etl::iu8string`, `etl::iu16string` or `etl::iu32string`.
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Where `FormatType` is `etl::format_spec`, `etl::wformat_spec`, `etl::u8format_spec`, `etl::u16format_spec` or `etl::u32format_spec`
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```cpp
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template <typename T>
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const StringType& to_string(const T value,
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StringType& str,
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const FormatType& format,
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const bool append = false)
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```
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---
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```cpp
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template <typename T>
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const StringType& to_string(const T value,
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uint32_t denominator_exponent,
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StringType& str,
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const FormatType& format,
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const bool append = false)
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```
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`value` The value to convert to a string.
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`denominator_exponent` The exponent of the value that is used to divide the value.
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`str` The string in with to place the rendered text.
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`format` The format specification.
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`append` If `true` then appends the text to the current string's content. Default `false`.
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From: `20.17.0`
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---
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## Examples
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Format as a hex character, minimum fill width of 8, fill with zeros
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```cpp
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etl::format_spec format;
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// Format as a hex character, minimum fill width of 8, fill with zeros.
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format.hex().width(8).fill('0');
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etl::string<8> text;
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// 'text' is set to "00123456"
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etl::to_string(1193046, text, format);
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---
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Format minimum fill width of 8, fill with space and three decimal digits
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etl::format_spec format;
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// Format minimum fill width of 8, fill with space and three decimal digits.
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format.width(8).fill(' ').precision(3);
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etl::string<8> text;
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// 'text' is set to " 3.142"
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etl::to_string(3.1415, text, format);
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---
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Format a floating point number
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etl::string<19> text = "The result is ";
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etl::to_string(3.1415, text, etl::format_spec().precision(3), true);
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// 'text' is set to "The result is 3.142"
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---
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Format an integral number and divide by 10000
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etl::string<19> text = "The result is ";
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etl::to_string(31415, 4U, text, etl::format_spec().precision(3), true);
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// 'text' is set to "The result is 3.142"
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```
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