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	Updates #5590 (which deprecated it, 2.5 years ago) Change-Id: I137e82855ee33d91e5639b909f7ca64e237ed6ba Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
		
			
				
	
	
		
			37 lines
		
	
	
		
			1.0 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			37 lines
		
	
	
		
			1.0 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright (c) Tailscale Inc & AUTHORS
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| // SPDX-License-Identifier: BSD-3-Clause
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| 
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| // Package mak helps make maps. It contains generic helpers to make/assign
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| // things, notably to maps, but also slices.
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| package mak
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| 
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| // Set populates an entry in a map, making the map if necessary.
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| //
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| // That is, it assigns (*m)[k] = v, making *m if it was nil.
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| func Set[K comparable, V any, T ~map[K]V](m *T, k K, v V) {
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| 	if *m == nil {
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| 		*m = make(map[K]V)
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| 	}
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| 	(*m)[k] = v
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| }
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| 
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| // NonNilSliceForJSON makes sure that *slicePtr is non-nil so it will
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| // won't be omitted from JSON serialization and possibly confuse JavaScript
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| // clients expecting it to be present.
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| func NonNilSliceForJSON[T any, S ~[]T](slicePtr *S) {
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| 	if *slicePtr != nil {
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| 		return
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| 	}
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| 	*slicePtr = make([]T, 0)
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| }
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| 
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| // NonNilMapForJSON makes sure that *slicePtr is non-nil so it will
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| // won't be omitted from JSON serialization and possibly confuse JavaScript
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| // clients expecting it to be present.
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| func NonNilMapForJSON[K comparable, V any, M ~map[K]V](mapPtr *M) {
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| 	if *mapPtr != nil {
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| 		return
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| 	}
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| 	*mapPtr = make(M)
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| }
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