// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package strings

import (
	
	
	
	
)

// A Builder is used to efficiently build a string using [Builder.Write] methods.
// It minimizes memory copying. The zero value is ready to use.
// Do not copy a non-zero Builder.
type Builder struct {
	addr *Builder // of receiver, to detect copies by value

	// External users should never get direct access to this buffer, since
	// the slice at some point will be converted to a string using unsafe, also
	// data between len(buf) and cap(buf) might be uninitialized.
	buf []byte
}

func ( *Builder) () {
	if .addr == nil {
		// This hack works around a failing of Go's escape analysis
		// that was causing b to escape and be heap allocated.
		// See issue 23382.
		// TODO: once issue 7921 is fixed, this should be reverted to
		// just "b.addr = b".
		.addr = (*Builder)(abi.NoEscape(unsafe.Pointer()))
	} else if .addr !=  {
		panic("strings: illegal use of non-zero Builder copied by value")
	}
}

// String returns the accumulated string.
func ( *Builder) () string {
	return unsafe.String(unsafe.SliceData(.buf), len(.buf))
}

// Len returns the number of accumulated bytes; b.Len() == len(b.String()).
func ( *Builder) () int { return len(.buf) }

// Cap returns the capacity of the builder's underlying byte slice. It is the
// total space allocated for the string being built and includes any bytes
// already written.
func ( *Builder) () int { return cap(.buf) }

// Reset resets the [Builder] to be empty.
func ( *Builder) () {
	.addr = nil
	.buf = nil
}

// grow copies the buffer to a new, larger buffer so that there are at least n
// bytes of capacity beyond len(b.buf).
func ( *Builder) ( int) {
	 := bytealg.MakeNoZero(2*cap(.buf) + )[:len(.buf)]
	copy(, .buf)
	.buf = 
}

// Grow grows b's capacity, if necessary, to guarantee space for
// another n bytes. After Grow(n), at least n bytes can be written to b
// without another allocation. If n is negative, Grow panics.
func ( *Builder) ( int) {
	.copyCheck()
	if  < 0 {
		panic("strings.Builder.Grow: negative count")
	}
	if cap(.buf)-len(.buf) <  {
		.grow()
	}
}

// Write appends the contents of p to b's buffer.
// Write always returns len(p), nil.
func ( *Builder) ( []byte) (int, error) {
	.copyCheck()
	.buf = append(.buf, ...)
	return len(), nil
}

// WriteByte appends the byte c to b's buffer.
// The returned error is always nil.
func ( *Builder) ( byte) error {
	.copyCheck()
	.buf = append(.buf, )
	return nil
}

// WriteRune appends the UTF-8 encoding of Unicode code point r to b's buffer.
// It returns the length of r and a nil error.
func ( *Builder) ( rune) (int, error) {
	.copyCheck()
	 := len(.buf)
	.buf = utf8.AppendRune(.buf, )
	return len(.buf) - , nil
}

// WriteString appends the contents of s to b's buffer.
// It returns the length of s and a nil error.
func ( *Builder) ( string) (int, error) {
	.copyCheck()
	.buf = append(.buf, ...)
	return len(), nil
}