1 files changed, 7 insertions, 6 deletions
diff --git a/absl/strings/ascii.h b/absl/strings/ascii.h
index ba6679bd..c238f4de 100644
--- a/absl/strings/ascii.h
+++ b/absl/strings/ascii.h
@@ -58,6 +58,7 @@
 
 #include "absl/base/attributes.h"
 #include "absl/base/config.h"
+#include "absl/base/nullability.h"
 #include "absl/strings/string_view.h"
 
 namespace absl {
@@ -166,7 +167,7 @@ inline char ascii_tolower(unsigned char c) {
 }
 
 // Converts the characters in `s` to lowercase, changing the contents of `s`.
-void AsciiStrToLower(std::string* s);
+void AsciiStrToLower(absl::Nonnull<std::string*> s);
 
 // Creates a lowercase string from a given absl::string_view.
 ABSL_MUST_USE_RESULT inline std::string AsciiStrToLower(absl::string_view s) {
@@ -184,7 +185,7 @@ inline char ascii_toupper(unsigned char c) {
 }
 
 // Converts the characters in `s` to uppercase, changing the contents of `s`.
-void AsciiStrToUpper(std::string* s);
+void AsciiStrToUpper(absl::Nonnull<std::string*> s);
 
 // Creates an uppercase string from a given absl::string_view.
 ABSL_MUST_USE_RESULT inline std::string AsciiStrToUpper(absl::string_view s) {
@@ -202,7 +203,7 @@ ABSL_MUST_USE_RESULT inline absl::string_view StripLeadingAsciiWhitespace(
 }
 
 // Strips in place whitespace from the beginning of the given string.
-inline void StripLeadingAsciiWhitespace(std::string* str) {
+inline void StripLeadingAsciiWhitespace(absl::Nonnull<std::string*> str) {
   auto it = std::find_if_not(str->begin(), str->end(), absl::ascii_isspace);
   str->erase(str->begin(), it);
 }
@@ -216,7 +217,7 @@ ABSL_MUST_USE_RESULT inline absl::string_view StripTrailingAsciiWhitespace(
 }
 
 // Strips in place whitespace from the end of the given string
-inline void StripTrailingAsciiWhitespace(std::string* str) {
+inline void StripTrailingAsciiWhitespace(absl::Nonnull<std::string*> str) {
   auto it = std::find_if_not(str->rbegin(), str->rend(), absl::ascii_isspace);
   str->erase(static_cast<size_t>(str->rend() - it));
 }
@@ -229,13 +230,13 @@ ABSL_MUST_USE_RESULT inline absl::string_view StripAsciiWhitespace(
 }
 
 // Strips in place whitespace from both ends of the given string
-inline void StripAsciiWhitespace(std::string* str) {
+inline void StripAsciiWhitespace(absl::Nonnull<std::string*> str) {
   StripTrailingAsciiWhitespace(str);
   StripLeadingAsciiWhitespace(str);
 }
 
 // Removes leading, trailing, and consecutive internal whitespace.
-void RemoveExtraAsciiWhitespace(std::string*);
+void RemoveExtraAsciiWhitespace(absl::Nonnull<std::string*> str);
 
 ABSL_NAMESPACE_END
 }  // namespace absl