error_ext.go raw

   1  // Copyright (c) 2020-2022 Uber Technologies, Inc.
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   3  // Permission is hereby granted, free of charge, to any person obtaining a copy
   4  // of this software and associated documentation files (the "Software"), to deal
   5  // in the Software without restriction, including without limitation the rights
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   7  // copies of the Software, and to permit persons to whom the Software is
   8  // furnished to do so, subject to the following conditions:
   9  //
  10  // The above copyright notice and this permission notice shall be included in
  11  // all copies or substantial portions of the Software.
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  13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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  16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  19  // THE SOFTWARE.
  20  
  21  package atomic
  22  
  23  // atomic.Value panics on nil inputs, or if the underlying type changes.
  24  // Stabilize by always storing a custom struct that we control.
  25  
  26  //go:generate bin/gen-atomicwrapper -name=Error -type=error -wrapped=Value -pack=packError -unpack=unpackError -compareandswap -swap -file=error.go
  27  
  28  type packedError struct{ Value error }
  29  
  30  func packError(v error) interface{} {
  31  	return packedError{v}
  32  }
  33  
  34  func unpackError(v interface{}) error {
  35  	if err, ok := v.(packedError); ok {
  36  		return err.Value
  37  	}
  38  	return nil
  39  }
  40