Index: clang-tidy/misc/StringConstructorCheck.cpp
===================================================================
--- clang-tidy/misc/StringConstructorCheck.cpp
+++ clang-tidy/misc/StringConstructorCheck.cpp
@@ -10,6 +10,7 @@
 #include "StringConstructorCheck.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Tooling/FixIt.h"
 
 using namespace clang::ast_matchers;
 
@@ -54,7 +55,7 @@
       isDefinition(),
       hasType(pointerType(pointee(isAnyCharacter(), isConstQualified()))),
       hasInitializer(ignoringParenImpCasts(BoundStringLiteral)));
-  auto ConstStrLiteral = expr(ignoringParenImpCasts(anyOf(
+  const auto ConstStrLiteral = expr(ignoringParenImpCasts(anyOf(
       BoundStringLiteral, declRefExpr(hasDeclaration(anyOf(
                               ConstPtrStrLiteralDecl, ConstStrLiteralDecl))))));
 
@@ -88,7 +89,7 @@
               // Detect the expression: string("...", 0);
               hasArgument(1, ZeroExpr.bind("empty-string")),
               // Detect the expression: string("...", -4);
-              hasArgument(1, NegativeExpr.bind("negative-length")),              
+              hasArgument(1, NegativeExpr.bind("negative-length")),
               // Detect the expression: string("lit", 0x1234567);
               hasArgument(1, LargeLengthExpr.bind("large-length")),
               // Detect the expression: string("lit", 5)
@@ -100,11 +101,18 @@
 }
 
 void StringConstructorCheck::check(const MatchFinder::MatchResult &Result) {
-  const auto *E = Result.Nodes.getNodeAs<Expr>("constructor");
+  const ASTContext &Ctx = *Result.Context;
+  const auto *E = Result.Nodes.getNodeAs<CXXConstructExpr>("constructor");
+  assert(E && "missing constructor expression");
   SourceLocation Loc = E->getLocStart();
 
   if (Result.Nodes.getNodeAs<Expr>("swapped-parameter")) {
-    diag(Loc, "constructor parameters are probably swapped");
+    const Expr* P0 = E->getArg(0);
+    const Expr* P1 = E->getArg(1);
+    diag(Loc, "string constructor parameters are probably swapped;"
+              " expecting string(count, character)")
+        << tooling::fixit::createReplacement(*P0, *P1, Ctx)
+        << tooling::fixit::createReplacement(*P1, *P0, Ctx);
   } else if (Result.Nodes.getNodeAs<Expr>("empty-string")) {
     diag(Loc, "constructor creating an empty string");
   } else if (Result.Nodes.getNodeAs<Expr>("negative-length")) {
Index: test/clang-tidy/misc-string-constructor.cpp
===================================================================
--- test/clang-tidy/misc-string-constructor.cpp
+++ test/clang-tidy/misc-string-constructor.cpp
@@ -21,9 +21,11 @@
 
 void Test() {
   std::string str('x', 4);
-  // CHECK-MESSAGES: [[@LINE-1]]:15: warning: constructor parameters are probably swapped [misc-string-constructor]
+  // CHECK-MESSAGES: [[@LINE-1]]:15: warning: string constructor parameters are probably swapped; expecting string(count, character) [misc-string-constructor]
+  // CHECK-FIXES: std::string str(4, 'x');  
   std::wstring wstr(L'x', 4);
-  // CHECK-MESSAGES: [[@LINE-1]]:16: warning: constructor parameters are probably swapped
+  // CHECK-MESSAGES: [[@LINE-1]]:16: warning: string constructor parameters are probably swapped
+  // CHECK-FIXES: std::wstring wstr(4, L'x');    
   std::string s0(0, 'x');
   // CHECK-MESSAGES: [[@LINE-1]]:15: warning: constructor creating an empty string
   std::string s1(-4, 'x');