gb_string.h: add gb_printf

1 files changed, 54 insertions, 0 deletions

diff --git a/gb_string.h b/gb_string.h
index a0058a5..bb665b2 100644
--- a/gb_string.h
+++ b/gb_string.h
@@ -198,6 +198,11 @@ int main(int argc, char **argv) {
 #ifndef GB_STRING_INCLUDE_GB_STRING_H
 #define GB_STRING_INCLUDE_GB_STRING_H
 
+#if !defined(GB_HAS_SNPRINTF) && \
+    (__STDC_VERSION__ >= 199101L || __cplusplus >= 201103L)
+#define GB_HAS_SNPRINTF
+#endif
+
 #ifndef GB_ALLOC
 #define GB_ALLOC(sz) malloc(sz)
 #define GB_FREE(ptr) free(ptr)
@@ -276,6 +281,10 @@ gbBool gb_strings_are_equal(gbString const lhs, gbString const rhs);
 
 gbString gb_trim_string(gbString str, char const *cut_set);
 
+#ifdef GB_HAS_SNPRINTF
+gbString gb_printf(gbString str, char const *fmt, ...);
+gbString gb_vprintf(gbString str, char const *fmt, va_list va);
+#endif
 
 #ifdef __cplusplus
 }
@@ -308,10 +317,22 @@ gb_inline void string_make_space_for(String& str, usize add_len) { str = gb_stri
 gb_inline usize string_allocation_size(const String str) { return gb_string_allocation_size(str); }
 gb_inline bool strings_are_equal(const String lhs, const String rhs) { return gb_strings_are_equal(lhs, rhs) == GB_TRUE; }
 gb_inline void trim_string(String& str, char const *cut_set) { str = gb_trim_string(str, cut_set); }
+
+#ifdef GB_HAS_SNPRINTF
+gb_inline void ref_vprintf(String& str, char const *fmt, va_list va) { str = gb_vprintf(str, fmt, va); }
+gb_inline void ref_printf(String& str, char const *fmt, ...) {
+	va_list va;
+	va_start(va, fmt);
+	ref_vprintf(str, fmt, va);
+	va_end(va);
+}
+#endif
+
 } /* namespace gb */
 #endif /* GB_STRING_CPP */
 #endif /* GB_STRING_H */
 #ifdef GB_STRING_IMPLEMENTATION
+
 static void gb_set_string_length(gbString str, gbUsize len) {
 	GB_STRING_HEADER(str)->len = len;
 }
@@ -320,6 +341,39 @@ static void gb_set_string_capacity(gbString str, gbUsize cap) {
 	GB_STRING_HEADER(str)->cap = cap;
 }
 
+#ifdef GB_HAS_SNPRINTF
+#include <limits.h>
+#include <stdio.h>
+
+gbString gb_vprintf(gbString s, char const *fmt, va_list va) {
+	va_list va2;
+	int nl;
+	gbUsize clen = gb_string_length(s);
+
+	va_copy(va2, va);
+	nl = vsnprintf(NULL, 0, fmt, va2);
+	va_end(va2);
+
+	if (nl < 0 || nl == INT_MAX) {
+		gb_free_string(s);
+		return GB_NULLPTR;
+	}
+
+	s = gb_string_make_space_for(s, nl + 1);
+	if (s == GB_NULLPTR)
+		return GB_NULLPTR;
+	vsnprintf(s + clen, nl + 1, fmt, va);
+	return s;
+}
+
+gbString gb_printf(gbString s, char const *fmt, ...) {
+	va_list va;
+	va_start(va, fmt);
+	s = gb_vprintf(s, fmt, va);
+	va_end(va);
+	return s;
+}
+#endif
 
 gbString gb_make_string_length(void const *init_str, gbUsize len) {
 	gbString str;