---
name: "FcCharSetMerge"
section: "3"
platform: "linux"
package: "fontconfig"
version: "2:2.18.3-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/FcCharSetMerge"
---

# FcCharSetMerge(3)

Merge charsets

## NAME

FcCharSetMerge - Merge charsets

## SYNOPSIS

**#include \<fontconfig/fontconfig.h\>**

**FcBool FcCharSetMerge (FcCharSet \****a***, const FcCharSet \****b***, FcBool \****changed***);**

## DESCRIPTION

Adds all chars in *b* to *a*. In other words, this is an in-place version of FcCharSetUnion. If *changed* is not NULL, then it returns whether any new chars from *b* were added to *a*. Returns FcFalse on failure, either when *a* is a constant set or from running out of memory.