Add a simple implementation of pj_is_nan() to proj_internal.h

2 files changed, 14 insertions, 0 deletions

diff --git a/src/pj_internal.c b/src/pj_internal.c
index 61905259..9cbbf20a 100644
--- a/src/pj_internal.c
+++ b/src/pj_internal.c
@@ -443,3 +443,15 @@ void proj_log_func (PJ_CONTEXT *ctx, void *app_data, PJ_LOG_FUNCTION logf) {
     if (0!=logf)
         ctx->logger = logf;
 }
+
+
+/*****************************************************************************/
+int pj_is_nan (double val) {
+/******************************************************************************
+    Returns 0 if not a NaN and non-zero if val is a NaN.
+
+    Provides an equivalent to isnan().
+******************************************************************************/
+    /* cppcheck-suppress duplicateExpression */
+    return val != val;
+}
diff --git a/src/proj_internal.h b/src/proj_internal.h
index 75893c33..b3843a59 100644
--- a/src/proj_internal.h
+++ b/src/proj_internal.h
@@ -130,6 +130,8 @@ void proj_fileapi_set (PJ *P, void *fileapi);
 const char * const *proj_get_searchpath(void);
 int    proj_get_path_count(void);
 
+int pj_is_nan (double val);
+
 #ifdef __cplusplus
 }
 #endif