From 1375f25de98bac0c40bdb85d6ca92b565bceeefb Mon Sep 17 00:00:00 2001
From: Thomas Krijnen <t.krijnen@gmail.com>
Date: Sat, 24 Jul 2021 11:19:07 +0200
Subject: [PATCH] #1564 typemap for optional string

---
 src/ifcwrap/utils/typemaps_in.i | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/ifcwrap/utils/typemaps_in.i b/src/ifcwrap/utils/typemaps_in.i
index 62f05ee390..a5ef36bcb6 100644
--- a/src/ifcwrap/utils/typemaps_in.i
+++ b/src/ifcwrap/utils/typemaps_in.i
@@ -239,4 +239,34 @@ CREATE_VECTOR_TYPEMAP_IN(std::string, STRING, str)
 
 %typemap(typecheck, precedence=SWIG_TYPECHECK_INTEGER) const Bnd_Box& {
    $1 = check_aggregate_of_aggregate_of_type($input, get_python_type<double>());
-}
\ No newline at end of file
+}
+
+%define CREATE_OPTIONAL_TYPEMAP_IN(template_type, express_name, python_name)
+
+	%typemap(in) const boost::optional<template_type>& {
+		if ($input == Py_None) {
+			(*$1) = boost::none;
+		} else if ($input->ob_type != get_python_type<template_type>()) {
+			SWIG_exception(SWIG_TypeError, "Optional " #express_name " needs a " #python_name " or None");
+		} else {
+			(*$1) = cast_pyobject<template_type>($input);
+		}
+	}
+
+	%typemap(typecheck,precedence=SWIG_TYPECHECK_INTEGER) const boost::optional<template_type>& {
+		$1 = ($input == Py_None || $input->ob_type == get_python_type<template_type>()) ? 1 : 0;
+	}
+
+	%typemap(arginit) const boost::optional<template_type>& {
+		$1 = new boost::optional<template_type>();
+	}
+
+	%typemap(freearg) const boost::optional<template_type>& {
+		delete $1;
+	}
+
+%enddef
+
+CREATE_OPTIONAL_TYPEMAP_IN(int, integer, int)
+CREATE_OPTIONAL_TYPEMAP_IN(double, real, float)
+CREATE_OPTIONAL_TYPEMAP_IN(std::string, string, str)
\ No newline at end of file