Improve document for std::fmt to format float type
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format! Precision description for float typeformat! Precision description for float type
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format! Precision description for float typeformat! Precision description for float type
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format! Precision description for float typestd::fmt to format float type
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Signed-off-by: Eval EXEC <execvy@gmail.com>
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r? libs-api since it seems like this is a new guarantee, which I'm not sure if we want to make. |
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| //! println!("{:.0}", 12.5f64); // 12 | ||
| //! println!("{:.0}", 12.3f64); // 12 | ||
| //! println!("{:.0}", 11.6f64); // 12 | ||
| //! println!("{:.0}", 11.5f64); // 12 | ||
| //! println!("{:.0}", 11.4f64); // 11 | ||
| //! println!("{:.0}", 10.5f64); // 10 | ||
| //! println!("{:.0}", 9.5f64); // 10 | ||
| //! println!("{:.0}", 8.5f64); // 8 | ||
| //! println!("{:.0}", 7.5f64); // 8 | ||
| //! println!("{:.0}", -7.5f64); // -8 | ||
| //! println!("{:.0}", -8.5f64); // -8 | ||
| //! println!("{:.0}", -9.5f64); // -10 | ||
| //! println!("{:.0}", -10.5f64);// -10 | ||
| //! println!("{:.0}", -11.4f64);// -11 | ||
| //! println!("{:.0}", -11.5f64);// -12 | ||
| //! println!("{:.0}", -11.6f64);// -12 | ||
| //! println!("{:.0}", -12.5f64);// -12 | ||
| //! println!("{:.0}", -12.6f64);// -13 | ||
| //! | ||
| //! println!("{:.1}", 3.33f64); // 3.3 | ||
| //! println!("{:.1}", -3.33f64);// -3.3 | ||
| //! println!("{:.1}", -3.55f64);// -3.5 | ||
| //! println!("{:.1}", 4.54f64); // 4.5 | ||
| //! println!("{:.1}", 4.55f64); // 4.5 | ||
| //! println!("{:.1}", 4.56f64); // 4.6 |
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This seems like an extremely excessive number of examples. Can {:.1} with 1.25 and 1.75 be sufficient to illustrate what you mean?
| @@ -273,6 +273,37 @@ | |||
| //! Hello, ` 123` has 3 right-aligned characters | |||
| //! ``` | |||
| //! | |||
| //! For the floating-point type, it employs the | |||
| //! [roundTiesToEven](https://en.m.wikipedia.org/wiki/Rounding#Rounding_half_to_even) convention: | |||
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What does the name "roundTiesToEven" refer to exactly? I did not find that anywhere in the link.
| //! For the floating-point type, it employs the | ||
| //! [roundTiesToEven](https://en.m.wikipedia.org/wiki/Rounding#Rounding_half_to_even) convention: |
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This is unlikely to be the most appropriate link because the subsection you linked to is describing the operation of rounding a float to an integer, which is different in general from formatting a float to a particular precision. The text even calls this out: a "more sophisticated mode [is] used when rounding to significant figures".
| //! println!("{:.1}", 4.55f64); // 4.5 | ||
| //! println!("{:.1}", 4.56f64); // 4.6 | ||
| //! ``` | ||
| //! |
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There is already a paragraph above which describes how precision applies to floating point types. It would make more sense to me to explain the rounding directly in that paragraph.
Lines 209 to 210 in bf0e22b
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@eval-exec any updates on this? |
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Closing this as inactive. Feel free to reöpen this pr or create a new pr if you get the time to work on this. Thanks |
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This PR want to close #112742