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7 Easy and safe casting from one type to another in Go
13 Cast is a library to convert between different go types in a consistent and easy way.
15 Cast provides simple functions to easily convert a number to a string, an
16 interface into a bool, etc. Cast does this intelligently when an obvious
17 conversion is possible. It doesn’t make any attempts to guess what you meant,
18 for example you can only convert a string to an int when it is a string
19 representation of an int such as “8”. Cast was developed for use in
20 [Hugo](http://hugo.spf13.com), a website engine which uses YAML, TOML or JSON
25 When working with dynamic data in Go you often need to cast or convert the data
26 from one type into another. Cast goes beyond just using type assertion (though
27 it uses that when possible) to provide a very straightforward and convenient
30 If you are working with interfaces to handle things like dynamic content
31 you’ll need an easy way to convert an interface into a given type. This
32 is the library for you.
34 If you are taking in data from YAML, TOML or JSON or other formats which lack
35 full types, then Cast is the library for you.
39 Cast provides a handful of To_____ methods. These methods will always return
40 the desired type. **If input is provided that will not convert to that type, the
41 0 or nil value for that type will be returned**.
43 Cast also provides identical methods To_____E. These return the same result as
44 the To_____ methods, plus an additional error which tells you if it successfully
45 converted. Using these methods you can tell the difference between when the
46 input matched the zero value or when the conversion failed and the zero value
49 The following examples are merely a sample of what is available. Please review
50 the code for a complete set.
52 ### Example ‘ToString’:
54 cast.ToString("mayonegg") // "mayonegg"
55 cast.ToString(8) // "8"
56 cast.ToString(8.31) // "8.31"
57 cast.ToString([]byte("one time")) // "one time"
58 cast.ToString(nil) // ""
60 var foo interface{} = "one more time"
61 cast.ToString(foo) // "one more time"
70 cast.ToInt(false) // 0
72 var eight interface{} = 8
73 cast.ToInt(eight) // 8