sqlx.Named fails when a named parameter is immediately followed by a PostgreSQL cast

[ludenyo]

Version

github.com/jmoiron/sqlx v1.4.0

Summary

sqlx.Named appears to misparse PostgreSQL cast syntax when it is attached directly to a named parameter, for example :boundary::jsonb.

Actual Behavior

The call returns:

err=unexpected ':' while reading named param at 16

Expected Behavior

The query should bind successfully, preserving the PostgreSQL cast, producing something equivalent to:

SELECT ?::jsonb AS boundary, '2026-05-01'::timestamptz AS starts_at;

with one bound argument for boundary.

Minimal Reproduction

package main

import (
    "fmt"

    "github.com/jmoiron/sqlx"
)

func main() {
    query := "SELECT :boundary::jsonb AS boundary, '2026-05-01'::timestamptz AS starts_at;"
    q, args, err := sqlx.Named(query, map[string]any{
        "boundary": `{"type":"Polygon","coordinates":[]}`,
    })

    fmt.Printf("query=%q\nargs=%#v\nerr=%v\n", q, args, err)
}