RowWithWeight.kt

import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.composed
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp

@Preview(showBackground = true)
@Composable
fun TestLayout() {
    Row {
        Column1(Modifier.weight(1f))
        Column2(Modifier.weight(1f))
    }
}

@Composable
fun Column1(modifier: Modifier = Modifier) {
    Column(modifier.withBorder()) {
        Button(onClick = { }) { Text("Button") }
        Button(onClick = { }) { Text("Button") }
    }
}

@Composable
fun Column2(modifier: Modifier = Modifier) {
    Column(modifier.withBorder()) {
        Text("Large Loremp Text Ipsum")
        Text("Large Loremp Text Ipsum")
    }
}

fun Modifier.withBorder() = composed { border(1.dp, Color.Red) }

Kind of interesting that weight modifier is only enabled in certain scopes like RowScope, ColumnScope. I had some problems trying to use weight inside a Card(because it hasn't a scope). Thanks!

Yep @CarlitosDroid, and that's because Composables are meant to be reusable, so you can't make assumptions about the container in which they will be. That's why the recommended approach is to always pass an optional modifier to the function. In that way, layout logic can be delegated to the container.