17 lines
1.8 KiB
Markdown
17 lines
1.8 KiB
Markdown
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Printing for Custom Types
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========================
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{{#include ../links.md}}
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To use custom types for [`print`] and [`debug`], or convert its value into a [string], it is necessary that the following
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functions be registered (assuming the custom type is `T : Display + Debug`):
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| Function | Signature | Typical implementation | Usage |
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| ----------- | ------------------------------------------------ | ------------------------------------- | --------------------------------------------------------------------------------------- |
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| `to_string` | `|s: &mut T| -> ImmutableString` | `s.to_string().into()` | Converts the custom type into a [string] |
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| `print` | `|s: &mut T| -> ImmutableString` | `s.to_string().into()` | Converts the custom type into a [string] for the [`print`](#print-and-debug) statement |
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| `debug` | `|s: &mut T| -> ImmutableString` | `format!("{:?}", s).into()` | Converts the custom type into a [string] for the [`debug`](#print-and-debug) statement |
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| `+` | `|s1: ImmutableString, s: T| -> ImmutableString` | `s1 + s` | Append the custom type to another [string], for `print("Answer: " + type);` usage |
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| `+` | `|s: T, s2: ImmutableString| -> ImmutableString` | `s.to_string().push_str(&s2).into();` | Append another [string] to the custom type, for `print(type + " is the answer");` usage |
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| `+=` | `|s1: &mut ImmutableString, s: T|` | `s1 += s.to_string()` | Append the custom type to an existing [string], for `s += type;` usage |
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