Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Appending a struct or an slice of structs to an interface slice isn't consistent? #42269

Closed
nazariinovak opened this issue Oct 29, 2020 · 1 comment

Comments

@nazariinovak
Copy link

@nazariinovak nazariinovak commented Oct 29, 2020

What version of Go are you using (go version)?

$ go version
go version go1.14.1 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output
$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/nazar/Library/Caches/go-build"
GOENV="/Users/nazar/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/nazar/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.14.1/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.14.1/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/nazar/go/src//go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/5b/q7mzw6g56m37ysqlwd2dlclm0000gn/T/go-build605073946=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

package main

import "fmt"

type A interface{}

type X string

func main() {
    sliceA := make([]A, 0, 0)
    sliceX := []X{"x1", "x2"}
    var appendedSlice []A
    appendedSlice = append(sliceA, sliceX[0], sliceX[1])  // (1) works
    appendedSlice = append(sliceA, sliceX...)             // (2) doesn't work
    fmt.Println(appendedSlice)

}

(Taken from this post https://stackoverflow.com/questions/53059641/notation-in-append-doesnt-work-for-appending-different-type-slices/53059817#53059817 , but I had the same problem)

What did you expect to see?

I expect for append to work the same way, when the thing I'm appending is a struct or a slice of struct, since it adds it dynamically one by one anyway. Shouldn't it work with the slice too?

What did you see instead?

cannot use sliceX (type []X) as type []A in append

@mvdan
Copy link
Member

@mvdan mvdan commented Oct 29, 2020

The Go project doesn't use the issue tracker for questions. See https://golang.org/wiki/Questions.

@mvdan mvdan closed this Oct 29, 2020
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Linked pull requests

Successfully merging a pull request may close this issue.

None yet
2 participants
You can’t perform that action at this time.