[core] Fix readability-* errors

As reported by clang-tidy-8.

4 files changed, 9 insertions, 9 deletions

diff --git a/src/mbgl/style/custom_tile_loader.cpp b/src/mbgl/style/custom_tile_loader.cpp
index d0b4dd58bc..eb17640dc8 100644
--- a/src/mbgl/style/custom_tile_loader.cpp
+++ b/src/mbgl/style/custom_tile_loader.cpp
@@ -52,7 +52,7 @@ void CustomTileLoader::removeTile(const OverscaledTileID& tileID) {
             break;
         }
     }
-    if (tileCallbacks->second.size() == 0) {
+    if (tileCallbacks->second.empty()) {
         tileCallbackMap.erase(tileCallbacks);
         dataCache.erase(tileID.canonical);
     }
diff --git a/src/mbgl/style/expression/compound_expression.cpp b/src/mbgl/style/expression/compound_expression.cpp
index b95dabfc84..2477fe7917 100644
--- a/src/mbgl/style/expression/compound_expression.cpp
+++ b/src/mbgl/style/expression/compound_expression.cpp
@@ -368,7 +368,7 @@ const auto& hasContextCompoundExpression() {
             };
         }
 
-        return params.feature->getValue(key) ? true : false;
+        return static_cast<bool>(params.feature->getValue(key));
     });
     return signature;
 }
@@ -996,7 +996,7 @@ std::string expectedTypesError(const Definitions& definitions,
     
     std::string actualTypes;
     for (const auto& arg : args) {
-        if (actualTypes.size() > 0) {
+        if (!actualTypes.empty()) {
             actualTypes += ", ";
         }
         actualTypes += toString(arg->getType());
@@ -1043,7 +1043,7 @@ static ParseResult createCompoundExpression(const Definitions& definitions,
             }
         }
 
-        if (signatureContext.getErrors().size() == 0) {
+        if (signatureContext.getErrors().empty()) {
             return ParseResult(std::make_unique<CompoundExpression>(*signature, std::move(args)));
         }
     }
diff --git a/src/mbgl/style/expression/parsing_context.cpp b/src/mbgl/style/expression/parsing_context.cpp
index ad1a46b8d6..56556d770c 100644
--- a/src/mbgl/style/expression/parsing_context.cpp
+++ b/src/mbgl/style/expression/parsing_context.cpp
@@ -207,7 +207,7 @@ ParseResult ParsingContext::parse(const Convertible& value,
             parsed = { annotate(std::move(*parsed), *expected, typeAnnotationOption.value_or(TypeAnnotationOption::coerce)) };
         } else {
             checkType((*parsed)->getType());
-            if (errors->size() > 0) {
+            if (!errors->empty()) {
                 return ParseResult();
             }
         }
@@ -265,13 +265,13 @@ ParseResult ParsingContext::parseLayerPropertyExpression(const Convertible& valu
     return parsed;
 }
 
-const std::string ParsingContext::getCombinedErrors() const {
+std::string ParsingContext::getCombinedErrors() const {
     std::string combinedError;
     for (const ParsingError& parsingError : *errors) {
-        if (combinedError.size() > 0) {
+        if (!combinedError.empty()) {
             combinedError += "\n";
         }
-        if (parsingError.key.size() > 0) {
+        if (!parsingError.key.empty()) {
             combinedError += parsingError.key + ": ";
         }
         combinedError += parsingError.message;
diff --git a/src/mbgl/style/sources/image_source_impl.hpp b/src/mbgl/style/sources/image_source_impl.hpp
index 1e1b005a32..d784464709 100644
--- a/src/mbgl/style/sources/image_source_impl.hpp
+++ b/src/mbgl/style/sources/image_source_impl.hpp
@@ -12,7 +12,7 @@ namespace style {
 class ImageSource::Impl : public Source::Impl {
 public:
     Impl(std::string id, std::array<LatLng, 4> coords);
-    Impl(const Impl& rhs, std::array<LatLng, 4> coords);
+    Impl(const Impl& other, std::array<LatLng, 4> coords);
     Impl(const Impl& rhs, PremultipliedImage&& image);
 
     ~Impl() final;